qblog4

This is an early draft of my new blog written in Quarto. It has entries from 1999 through 2025.

You can find earlier entries at

Some of the pages on these sites, are completely broken, partially broken, have missing images, etc. My goal is to use the new site to fix up every bad page and crosslink those files to the old ones. With over 2,200 pages, this will take a while. Refer to the [about page] to get a bit more information about the older sites.

I also have an early draft of a book, Jump Start Statistics

 

Scientific data

*Recommendation
2025
Datasets
This journal is devoted to documenting datasets of great scientific or medical importance. They also have articles about the policies, standards, and mechanics of data…
Sep 7, 2025
Steve Simon

 

A big milestone for quarto

*Blog post
Website details
Over the 27 years that this website has been in existence, I have used a variety of different software systems to produce web pages. In 2019, I decided to unite these…
Aug 31, 2025
Steve Simon

 

Examples of some simple regular expressions

*Blog post
Data management
I wanted to use some regular expressions to do a word count for every files on my website. First, I had to remove anything that was not a word. The simplest way is to…
Aug 31, 2025
Steve Simon

 

Raynald’s SPSS Tools

*Blog post
2025
Being updated
Data management
SPSS software
Raynald Levesque. Raynald’s SPSS Tools. Available in html format.
Aug 21, 2025
Steve Simon

 

Definition, Descriptive statistics

*Definitions
2025
Descriptive statistics
Descriptive statistics: Numerical summaries from a sample that characterize that sample without any effort to test a particular hypothesis.
Aug 11, 2025
Steve Simon

 

Definition, Normal distribution

*Definitions
2025
Probability concepts
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 11, 2025
Steve Simon

 

A free regex book

*Recommendation
2025
String data
This book comes highly recommended by others who know more abour regex (regular expressions) than I do. To my delight, this book is also available for free in pdf format.
Aug 11, 2025
Steve Simon

 

Definition, Adverse event

*Definitions
2022
Clinical trials
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 10, 2025
Steve Simon

 

Psychological Science

*Recommendation
Datasets
This journal encourages authors to share their data and could be a nice resource for teaching examples.
Aug 4, 2025
Steve Simon

 

Data package

*Recommendation
Datasets
Data Package is an effort to standardize descriptions about data that are simple but also able to handle extensions.
Aug 3, 2025
Steve Simon

 

regressinator: Simulate and Diagnose (Generalized) Linear Models

Recommendation
An R package that allows you to explore different simulations of generalized linear models.
Aug 3, 2025
Steve Simon

 

Score Network

*Recommendation
Datasets
The Score Network is a joint effort spread across several Universities to present interesting and well-documented datasets that can be used for sports analytics.
Aug 3, 2025
Steve Simon

 

tidytuesday project

*Recommendation
Datasets
Every Tuesday, this site releases an interesting dataset and encourages interesting analyses. More information is available [here][ref-harmon-nodate-1].
Aug 3, 2025
Steve Simon

 

MIMIC-III Clinical Database Demo

*Recommendation
2025
datasets
SQL
The MIMIC-III database is a massive database of health care records for over 40,000 patients at Beth Israel Deaconess Medical Center from 2001 to 2012. The information is…
Jul 11, 2025
Steve Simon

 

Curve fitting - xkcd

Recommendation
This is an introduction that I wrote for a webinar. Let me share it here. I started with a cartoon from the xkcd site of Scott Munro. Scott Munro produces comics that poke…
Apr 13, 2025
Steve Simon

 

Working with invalid names in R

Blog post
The R programming language has a few rules about names that you can assign for various objects. This can cause some issues with data frames and tibbles that you might be…
Apr 9, 2025
Steve Simon

 

Resources for software engineering

*Blog post
2025
Software engineering
I attended a great webinar by Alex Reinhart, From Code to Products - Software Engineering for Data Science. He is part of the Delphi Group at Carnegie Mellon University, a…
Apr 3, 2025
Steve Simon

 

Tidyverse style guide

*Recommendation
2025
R programming
A style guide is a list of standards that you should follow to make your R code consistent and readable. The tidyverse style guide is one example and most of the…
Apr 3, 2025
Steve Simon

 

Multidimensional Deprivation Index

*Recommendation
2025
Datasets
The Census Bureau has an “unofficial” product called the Multidimensional Deprivation Index (MDI), which is described in numerous working papers. This measure is only…
Mar 25, 2025
Steve Simon

 

Cleaning height and weight measurements

*Recommendation
2025
R programming
The R package growthcleanr will review longitudinal data (including data unevenly spaced over time) on heights and weights for children to find individual observations that…
Mar 22, 2025
Steve Simon

 

Qualitative Research. The “What,” “Why,” “Who,” and “How”!

*Recommendation
2025
Qualitative research
This is a very nice “how to” description of qualitative research.
Mar 19, 2025
Steve Simon

 

Geocomputation with R

*Recommendation
2025
R programming
I was browsing through Chapter 6 of the [ggplot2 book][wickham-2025] by Hadley Wickham, Danielle Navarro, and Thomas Lin Pedersen, which is itself interesting reading. It…
Mar 2, 2025
Steve Simon

 

Choices with the group_by and summarize functions

*Blog post
2025
R programming
uses R code
You have an interesting choice in an R program When you use the group_by function with two or more arguments and follow that with the summarize function. Here is a practical…
Feb 11, 2025
Steve Simon

 

Functions to make plain R output look nicer

*Blog post
2025
R programming
uses R code
Most of the statistical summary functions in R produce plain vanilla output. That’s actually good because it allows you to customize things the way you like. I have been…
Feb 9, 2025
Steve Simon

 

Image of messy filing system

*Recommendation
2025
Software engineering
This image, available under a Creative Common attribution license, illustrates a chaotic filing system. This will help bring home the point that if you set up a directory…
Jan 29, 2025
Steve Simon

 

Engaging People Most Affected by the Problem

*Recommendation
2025
Human side of statistics
This is a nice description with real-world examples of how to involve the community in the planning and execution of your research.
Jan 14, 2025
Steve Simon

 

How to make beautiful tables in R

*Recommendation
2024
R programming
The basic tables you get when simply printing data and or analysis results are okay, but not publication quality. There are several nice packages in R that can produce…
Dec 21, 2024
Steve Simon

 

Whitespace character

*Recommendation
2024
Text data
I have often struggled with processing text data in R that has the non-breaking space character (ASCII 160). It turns out that there are about a dozen other characters that…
Dec 19, 2024
Steve Simon

 

StatsUpAI Datasets

*Recommendation
2024
Datasets
This is a curated repository of various dataset repositories in elctronic health records, genomics, imaging, microbiome, clinical trials, transcriptomics, and proteomics.
Dec 18, 2024
Steve Simon

 

CORGIS: The Collection of Really Great, Interesting, Situated Datasets

*Recommendation
2024
Datasets
Some rather eclectic (and interesting) datasets. All data are stored in a consistent comma-delimited format with very good descriptions of the individual variables.
Dec 13, 2024
Steve Simon

 

Using SQL instead of R

*Blog post
2024
SQL
R sotware
The December 12, 2024 digest of the R help mailing list (Vol 262, Issue 9) had an interesting question. Let me try to paraphrase things here. A researcher had just started…
Dec 12, 2024
Steve Simon

 

Survival analysis sample size calculation

*Blog post
2024
Sample size justification
Survival analysis
Uses R code
Someone asked about getting a sample size for a survival analysis project. Here is the scenario. This is a two group comparison. The control group is expected to see 75%…
Nov 26, 2024
Steve Simon

 

Data Science Dojo datasets

*Recommendation
2024
datasets
Data Science Dojo is a company that provides training classes in (you guessed it!) data science. They have stored a nice collection of datasets for learning data science…
Nov 9, 2024
Steve Simon

 

A collection of Python tools to help with pregnancy research

*Recommendation
2024
Python programming
A graduate student in our department wrote a nice package to extract information about pregnancy outcomes from electronic health records databases.
Nov 7, 2024
Steve Simon

 

Comic take on error bars

*Recommendation
2024
Graphical display
This comic strip by Scott Munro pokes fun at how error bars are perceived by some as imparting profound knowledge. Scott Munro publishes his comics under a Creative Commons…
Nov 7, 2024
Steve Simon

 

Enthusiasm at the start…

*Quotation
2024
Human side of statistics
An earlier version of this page was published on new.pmean.com.
Nov 2, 2024
Steve Simon

 

Resources for presenting research

*Recommendation
2024
Presenting research
Here are a few articles that I am recommending during my talk on research presentations.
Nov 1, 2024
Steve Simon

 

Data masking in R

*Recommendation
2024
R programming
One major innovation of tidyverse is the use of non-standard evaluation. It allows you to avoid a lot of repetition of dataframe names in R code. I wrote a page about…
Oct 5, 2024
Steve Simon

 

Understanding the Odds Ratio and the Relative Risk

*Recommendation
2024
Measures of risk
There is a lot of controversy over the use of the odds ratio versus the relative risk. I wrote a brief article on this and explained settings where you should use the odds…
Oct 5, 2024
Steve Simon

 

From R Markdown to Quarto

*Recommendation
2024
R programming
I attended a short course, From R Markdown to Quarto, which provided a nice introduction to Quarto, a system for producing documents in a wide range of formats that…
Oct 3, 2024
Steve Simon

 

closeread

*Recommendation
2024
R programming
You can create an interactive document that changes as you scroll through it, highlighting certain features in text of images using the closeread app, an extension for Quarto.
Oct 3, 2024
Steve Simon

 

Cleveland Clinic Statistical Dataset Repository

*Recommendation
2024
Datasets
An article in the Journal of Statistics Education describes the development of a repository for real-world datasets associated with actual peer-reviewed publications. You…
Sep 25, 2024
Steve Simon

 

String Encoding and R

*Recommendation
2024
R programming
![Figure 1. Excerpt from blog post](http://www.pmean.com/new-images/24/string-encoding-01.png{width=80%}
Sep 8, 2024
Steve Simon

 

A 50 word biography

*Blog post
2024
Porfessional details
I was asked to write a biography for a short newsletter article that I sent in. The only trick was that it had to be 50 words. Here’s what I wrote (actually 52 words).
Sep 4, 2024
Steve Simon

 

Tracking variable modifications in SAS

*Blog post
2024
Data management
SAS software
A student in my Introduction to SAS class posed an interesting question: after you transform some of your variables, how do you keep track of what the original variable is…
Jul 28, 2024
Steve Simon

 

Linegraph options in SAS

*Blog post
2024
SAS software
Several of my students wanted information on how to modify graphs in SAS. I’m glad they asked, because the worst thing you can do with any software is to take the graph that…
Jul 22, 2024
Steve Simon

 

Scatterplot options in SAS

*Blog post
2024
SAS software
Several of my students wanted information on how to modify graphs in SAS. I’m glad they asked, because the worst thing you can do with any software is to take the graph that…
Jul 21, 2024
Steve Simon

 

Histogram options in SAS

*Blog post
2024
SAS software
Several of my students wanted information on how to modify graphs in SAS. I’m glad they asked, because the worst thing you can do with any software is to take the graph that…
Jul 19, 2024
Steve Simon

 

What happens when you leave out a semicolon in SAS?

*Blog post
2024
SAS software
SAS uses semicolons at the end of each statement. This allows you to stretch a long program statement across two or more lines. I want to show what happens when you forget a…
Jul 15, 2024
Steve Simon

 

A gentle introduction to SHAP values in R

*Recommendation
2024
Interpretable machine learning
SHAP values provide you a way to interpret the impact of individual independent variables in a variety of “black box” machine learning models, such as Random Forest. It…
Jul 10, 2024
Steve Simon

 

Effect sizes in linear regression and analysis of variance

Blog post
I have been asked to produce effect size measures for a linear regression model. I do not like effect size measures but people who are a lot smarter than me do ask for them…
Jul 8, 2024
Steve Simon

 

ggtern: Ternary Diagrams Using ggplot2

*Recommendation
2024
Graphical display
Ternary plots display three proportions which must sum to 1. It uses a triangular plotting area where each corner of the triangle represents an extreme with a single…
Jul 6, 2024
Steve Simon

 

AI and the Meaning of Life

*Recommendation
2024
Artificial intelligence
The Existential Comics website, written by Corey Mohler, is an exploration of major ideas in Philosophy that places famous Philosophers of the past in modern contexts to an…
Jul 3, 2024
Steve Simon

 

Nice layout for comparison of categorical outcomes

*Blog post
2024
Incomplete pages
R programming
Uses R code
While it is easy to get R to produce descriptive statistics for categorical outcomes in a research study, it is a bit harder to get R to produce a layout that is…
Jun 27, 2024
Steve Simon

 

Writing the discussion section of a research publication

*Blog post
2024
Writing research papers
I am bringing together resources for various chapters in my book proposal. One of the chapters (chapter 15 in one proposed outline and section 3.7 a different outline) is on…
Jun 20, 2024
Steve Simon

 

Infovis and Statistical Graphics: Different Goals, Different Looks

*Recommendation
2024
Being updated
The authors draw a distinction between Information Visualization (infovis) and Statistical Graphics. The goals of Infovis experts are to grab attention and tell a story. The…
Jun 14, 2024
Steve Simon

 

An epidemic of scientific fakery threatens to overwhelm publishers

*Recommendation
2024
Fraud in research
The number of retracted papers has grown rapidly over the past year. Marcus and Oransky, creators of the Retraction Watch website, explain why this is happening and offer…
Jun 11, 2024
Steve Simon

 

Different end times in survival data

*Blog post
2024
Ask Professor Mean
Survival analysis
Uses R code
Dear Professor Mean, I am running a survival analysis with two groups and one group was followed for 190 days and the other for 225 days. Would that cause any bias?
May 28, 2024
Steve Simon

 

R datasets

*Recommendation
2024
Datasets
R programming
Both base R and many of the R packages have datasets included which help illustrate the use of various features in R. This site consolidates all of those datasets in a…
May 21, 2024
Steve Simon

Illustrating splines using the diamond pricing dataset

*Blog post
2024
Nonlinear regression
R programming
Splines provide a useful way to model relationships that are more complex than a simple linear relationship. They work in a variety of regression models. Here is an…
May 7, 2024
Steve Simon

Illustrating the lasso model using the Worcester Heart Attack Study

*Blog post
2024
Survival analysis
R programming
Uses R code
The lasso model allows you to effectively identify important features in a large regression model. Here is an illustration of how to use a the lasso model with survival data…
May 7, 2024
Steve Simon

Illustrating splines using the Worcester Heart Attack Study

*Blog post
2024
Incomplete pages
Survival analysis
R programming
Uses R code
Splines provide a useful way to model relationships that are more complex than a simple linear relationship. They work in a variety of regression models. Here is an…
May 7, 2024
Steve Simon

 

Illustrating imputation of missing data using the Titanic dataset

*Blog post
2024
Missing data
R programming
Using R code
Multiple imputation is a way to properly account for missing values without causing bias. Simpler forms of imputation, such as replacing missing values with the mean of the…
May 7, 2024
Steve Simon

Illustrating splines using the Titanic dataset

*Blog post
2024
Nonlinear regression
R programming
Using R code
Splines provide a useful way to model relationships that are more complex than a simple linear relationship. They work in a variety of regression models. Here is an…
May 7, 2024
Steve Simon

 

A tricky program to debug

*Blog post
2024
R programming
I’ve had a couple of students bring me R programs that did not work. Looking at the output, I could not figure out why they did not work. It turns out that you have to look…
Apr 26, 2024
Steve Simon

 

Center for Advancement and Dissemination of Intervention Optimization

*Recommendation
2024
Research design
Many behavioral interventions include several discrete components. You should consider trying to optimize the mix of these components. Intervention Optimization provides a…
Apr 18, 2024
Steve Simon

 

Mendeley data

*Recommendation
2024
Datasets
While there are several websites that offer repositories for datasets associated with peer-reviewed publications, this one seems to offer a better set of choices: full and…
Apr 7, 2024
Steve Simon

 

JBI Manual for Evidence Synthesis

*Recommendation
2024
Systematic overviews
A nice overview of a broad range of systematic overviews for qualitative evidence, evidence of effectiveness, textual evidence, economic evidence, and scoping reviews.
Mar 29, 2024
Steve Simon

 

R Inferno

*Recommendation
2024
R programming
Warning! This document is not for those who are fairly new to R. I don’t want you to get scared away!
Mar 25, 2024
Steve Simon

 

Biography for 2024 talk

*Blog post
2024
Personal details
I’m tentatively scheduled to give a webinar for the Consulting Section of the American Statistical Association on May 2. They wanted a short biography of me that they could…
Mar 23, 2024
Steve Simon

 

Encoding example in R

*Blog post
2024
Data management
Alphabets other than English require special characters. Computers have evolved many different ways to handle these special characters.
Mar 23, 2024
Steve Simon

 

Finding customers webinar

*Blog post
2024
Human side of statistics
I am tentatively giving a webinar for the Consulting Section of the American Statistical Association on May 2. Here is the title and abstract.
Mar 22, 2024
Steve Simon

 

Security policies at my job

*Blog post
2024
Being updated
There are several important security policies at my job that are worth noting here. They provide good general guidance for anyone working with sensitive data.
Mar 20, 2024
Steve Simon

 

“Final”.doc

*Recommendation
2024
Software engineering
PhD Comics is satirical look at life as a graduate student. This particular comic resonated with me, so I am sharing it here. Although this comic strip is not directly about…
Feb 2, 2024
Steve Simon

 

HCL-Based Color Palettes

*Recommendation
2024
Being updated
{width=80%)
Feb 2, 2024
Steve Simon

 

A review of spline function procedures

*Recommendation
2024
Linear regression
A very nice and not too technical overview of the various spline models and the libraries in R that implement them.
Jan 25, 2024
Steve Simon

 

The Art of LaTeX

*Recommendation
2024
Writing research papers
I use LaTeX to create mathematical formulas and it does a great job at it. There are so many features, however, that could make my formulas look even nicer. This detailed…
Jan 18, 2024
Steve Simon

 

Distribution-free Bayesian Analysis

*Recommendation
2024
Bayesian statistics
The commonly used examples of Bayesian data analysis will require specific distributional assumptions. These can be relaxed somewhat. But it is possible to provide a…
Jan 3, 2024
Steve Simon

 

The parsimony principle…

*Quotation
2024
Modeling issues
An earlier version of this page was published on new.pmean.com.
Jan 3, 2024
Steve Simon

 

With four parameters…

*Quotation
2024
Being updated
An earlier version of this page was published on new.pmean.com.
Jan 3, 2024
Steve Simon

 

Suggestions for topics on a methodology paper

*Blog post
2023
Research methodology
A colleague of mine is guest editor for journal that is preparing special issue on research methodology. He wanted to know if I was interested in contributing a paer, and of…
Dec 11, 2023
Steve Simon

 

Finding good research examples

*Blog post
2023
Information searching
You find yourself using what, to you, is a new statistical approach, multiple imputation, and you’re uncertain about how to approach it. You’re not sure what options you…
Dec 7, 2023
Steve Simon

 

The best reasons to run a pilot study

*Blog post
2023
Pilot studies
There’s a common saying among pediatricians: children are not little adults. You can’t take a drug therapy that works in adults and scale it down to a kid-sized treatment.…
Dec 6, 2023
Steve Simon

What is a partial correlation?

*Blog post
2023
Correlation
Uses R code
The concept of controlling for a third variable is an important one to understand in Statistics. When you are looking at data without the benefit of randomization, sometimes…
Dec 5, 2023
Steve Simon

 

Arrow R Package

*Recommendation
2023
R software
Apache Arrow is a system for storing columnar data that is fast and can handle very large files. I have not had a chance to work with this format, but it looks very…
Nov 8, 2023
Steve Simon

 

Joining Posit’s Polyglot Data Science Mission

*Recommendation
2023
Python programming
Wes McKinney describes much of his early work with open source software and his recent decision to join Posit.
Nov 8, 2023
Steve Simon

 

Standardized survival functions

*Recommendation
2023
Being updated
Getting a survival function that is properly adjusted for covariates is tricky. This webpage documents how you could do this using a Stata macro, stmp_standsurv.
Nov 8, 2023
Steve Simon

 

Documenting a sample size justification

*Blog post
2023
Sample size justification
If you provide justification for a proposed sample size, you should include enough information to allow others to reproduce your calculations. Here is a brief overview of…
Nov 6, 2023
Steve Simon

 

ggplot2: Elegant Graphics for Data Analysis (3e)

*Recommendation
2023
Graphical display
Online version of the third edition of a book by the developers of ggplot2. It is described (as of November 2023) as a “work-in-progress”.
Nov 3, 2023
Steve Simon

 

The Not So Short Introduction to LaTeX

*Recommendation
2023
Writing research papers
LaTex provides a great environment for publishing mathematical documents. Chapter 3 of this guide, which shows how to write publication ready mathematical formulas, is…
Nov 1, 2023
Steve Simon

 

McNemar’s test

*Blog post
2023
Measuring benefit and risk
Uses R code
I mentioned McNemar’s test in a short article for my Monthly Mean newsletter. Here are more details about this test.
Oct 31, 2023
Steve Simon

 

Illustration of the rule of 16

*Blog post
2023
Sample size justification
The rule of 16 is a convenient rule to give quick estimate of the sample size that you might need in a study. It states that if you want to conduct a study with enough power…
Oct 17, 2023
Steve Simon

 

Using R to automate file uploads

*Blog post
2023
R software
I am trying to automate some tasks that will streamline my workload. One of those tasks is uploading files to my website. I am just starting to explore how this can be done.…
Oct 3, 2023
Steve Simon

 

UM system resources for generative AI

*Blog post
2023
Artificial intelligence
I attended a webinar sponsored by Missouri Online on the use of generative AI in education. The author referred to two resources that they provide.
Sep 28, 2023
Steve Simon

 

Key data privacy references

*Blog post
2023
Privacy in research
I attended a webinar on data privacy and the speakers opened with a series of seminal articles about how easy it is to re-identify data that you might have thought was…
Sep 28, 2023
Steve Simon

Too many colors spoil the graph

*Blog post
2023
Being updated
Uses R code
When you draw a graph, either a bar chart, a scatterplot, or even a pie chart, you have the choice of a broad range of colors that you can use. R, for example, has 657…
Sep 12, 2023
Steve Simon

 

Information for a new research grant

*Blog post
2023
Professional details
I may be working with a consulting group, Mountain Whisper Light, on a grant proposal to be sent to the Department of Natural Resources in the state of Washington. I don’t…
Sep 6, 2023
Steve Simon

Using a linear Taylor series approximation to estimate rounding error

*Blog post
2023
Mathematics
Uses R code
When I run, I have an app that announces the distance traveled (in kilometers) at the end of every minute. But since the app rounds to one decimal place, there is a bit of…
Sep 2, 2023
Steve Simon

 

Introduction to Data Technologies

*Recommendation
2023
Data management
R software
SQL software
An interesting book, published under an open source license and available in html or pdf versions. It is a rather eclectic mix of html, css, SQL, and R. The guiding theme is…
Aug 31, 2023
Steve Simon

 

Displaying SPSS syntax commands

*Blog post
2023
SPSS software
In SPSS, you can do all of your data manipulations and data analysis using the menus and dialog boxes. You also could use program code, which SPSS calls “syntax”. Most SPSS…
Aug 30, 2023
Steve Simon

 

A few details about myself

*Blog post
2023
Professional details
I was asked to provide a few details about myself (a bio blurb) to be used at the first graduate research seminar for Fall semester 2023.
Aug 19, 2023
Steve Simon

 

How scientists work to correct the record when there is an error in a paper

*Recommendation
2023
Ethics in research
A recent scandal involving the former president of Stanford, Marc Tessier-Lavigne, offers an opportunity to see how the research enterprise works to correct errors. To be…
Aug 3, 2023
Steve Simon

 

Modern Data Science with R

*Recommendation
2023
Teaching resources
A very complete book available for free online.
Jul 28, 2023
Steve Simon

 

Reshaping longitudinal data in SAS

*Blog post
2023
SAS software
If you work with longitudinal data, you may see the data arranged in a tall and thin format or in a short and fat format. The tall and thin format is useful for some data…
Jul 22, 2023
Steve Simon

 

Primer on Python for R Users

*Recommendation
2023
Python programming
Some of the topics are a bit abstract, but in general, a quite nice description of how Python differs from R.
Jul 14, 2023

Feature Engineering and Selection: A Practical Approach for Predictive Models

*Recommendation
2023
Data mining
This book can be bought, but is also available for free in html format. Here is a brief description taken from the Amazon page for this book. “The process of developing…
Jul 12, 2023

 

Swarm plot examples

*Blog post
2023
Graphical display
I came across a new type of plot yesterday, a swarm plot. It looks like an interesting alternative to jittering. You can create these graphs using the seaborn library of…
Jul 12, 2023
Steve Simon

 

Pediatric Pandemic Network

*Recommendation
2023
Children in research
A colleague of mine mentioned this research consortium of children’s hospitals, including Children’s Mercy. They fund a variety of research projects and I might work with…
Jul 10, 2023

 

Another pitch for my graphic novel project

*Blog post
2023
Ethics in research
I sent out an email recently about a project I have been thinking about doing for quite a few years. Here is the general text of the email with a few changes to avoid…
Jul 6, 2023
Steve Simon

 

Transforming healthcare research with technology’s latest capabilities

*Recommendation
2023
Important statisticians
Well, I filed this under the tage “Important statisticians” but this interview for the Oracle Research in Action podcast with Mark Hoffman is stretching that tag a bit. Mark…
Jul 5, 2023

 

SAS Webinars

*Recommendation
2023
SAS software
SAS Institute offers a variety of live and recorded webinars that highlight important issues in Statistics and how products from SAS Institute can help with them.…
Jul 5, 2023

 

Florence Nightingale’s legacy lives on

*Recommendation
2023
Important statisticians
A nice summary of the importance of Statistics and Evidence-Based Health Care to the work of Florence Nightingale.
Jun 12, 2023

 

Version control basics, updating a local project using git

*Blog post
2023
Software engineering
This is part of series of articles on how to set up and use version control on your computer. There are many systems for version control. In these articles, you will use a…
May 30, 2023
Steve Simon

 

Version control basics, creating a personal repository

*Blog post
2023
Software engineering
This page has been replaced with two other pages, git-local-installation and git-local-updates. I also hope to add a few more pages about ths in the future.
May 30, 2023
Steve Simon

 

Version control basics, installing a local version of git

*Blog post
2023
Software engineering
This is part of series of articles on how to set up and use version control on your computer. There are many systems for version control. In these articles, you will use a…
May 28, 2023
Steve Simon

 

Version control basics, updating a local project using git

*Blog post
2023
Incomplete pages
Software engineering
This page has been replaced with two other pages, git-local-installation and git-local-updates. I also hope to add a few more pages about ths in the future.
May 28, 2023
Steve Simon

 

How can I estimate relative risk using GLM for common outcomes in cohort studies

*Recommendation
2023
Measuring benefit and risk
It is easy to get odds ratios from logistic regression, but what do you do when you want to estimate relative risks instead. There are several possible solutions, and this…
May 24, 2023

 

Resources mentioned during SDSS

*Blog post
2023
Teaching resources
I want to list some of the resources mentioned at various talks during SDSS 2023.
May 24, 2023

 

NLM Grants for Scholarly Works in Biomedicine and Health

*Blog post
2023
Writing research grants
The National Library of Medicine just released a Notice of Funding Opportunity, NLM Grants for Scholarly Works in Biomedicine and Health, PAR-23-183. This is to help prepare…
May 19, 2023

 

Overview of Randomization Tests

*Recommendation
2023
Statistical computing
This is a detailed overview of randomization tests. It starts with the general philosophy behind randomization tests. Then it provides concrete examples in a variety of…
May 11, 2023

 

Re-Reading Deming’s 14 Points in the Era of Data Science

*Recommendation
2023
Data science
Quality improvement
An interesting attempt to adapt Deming’s Fourteen Points, written over 40 years ago, to modern data science.
May 1, 2023

 

Statistical Literacy: A Study of Confounding

*Recommendation
2023
Risk adjustment
THe author reviews many articles on statistical literacy and notes some interesting trends in how frequently the term “confounding” appears in those articles. He then offers…
May 1, 2023

 

Starting to think about AI Fairness

*Recommendation
2023
Data science
Some algorithms in Artificial Intelligence (AI) have been shown to cause harm to already disadvantaged groups. Fixing this is not easy. In particular, deciding when an…
Apr 20, 2023

 

Non-standard evaluation inside functions and loops

*Blog post
2023
R software
Uses R code
One of the big changes that the tidyverse made to the R programming language is the use of non-standard evaluation (NSE). This is sometimes described more explicitly as tidy…
Apr 4, 2023

 

An Introduction to the Harrell”verse”

*Recommendation
2023
Linear regression
Frank Harrell has packed in some pretty nice features in his Hmisc and rms packages. This post outlines some of these using practical examples.
Mar 31, 2023

 

Magrittr aliases

*Recommendation
2023
R software
When you are using pipes in R, sometimes you need access to a function that doesn’t look like a function, such as the function to set names for a data frame. The programmers…
Mar 31, 2023

 

A mixture of normal distributions

*Blog post
2023
Statistical theory
There is a simple theoretical result involving a mixture of normal distributions. If you select a normal distribution with a mean of zero and let the precision of that…
Mar 24, 2023

The hedging hyperprior for the normal distribution: unknown mean, unknown precision

*Blog post
2023
Bayesian statistics
Uses R code
I want to write a paper about the hedging hyperprior. I need to work out some simple examples first. Here is an example involving the normal distribution.
Mar 21, 2023

The hedging hyperprior for the normal distribution: known mean, unknown precision

*Blog post
2023
Bayesian statistics
Uses R code
I want to write a paper about the hedging hyperprior. I need to work out some simple examples first. Here is an example involving the normal distribution.
Mar 14, 2023

 

The modified power prior

*Blog post
2023
Bayesian statistics
Incomplete pages
Uses R code
I want to write a paper about the hedging hyperprior. Here is a brief description of an approach it is comparable to, the modified power prior.
Mar 4, 2023

 

A thank you from BMJ Open

*Blog post
2023
Professional details
I don’t do my fair share of peer-reviews, but I did do one recently and got a nice thank you note on Valentine’s Day. I am reproducing the text here, so I can refer to it…
Feb 28, 2023

The hedging hyperprior for the exponential distribution

*Blog post
2023
Bayesian statistics
Uses R code
I want to write a paper about the hedging hyperprior. I need to work out some simple examples first. Here is an example involving the exponential distribution.
Feb 28, 2023

The hedging hyperprior for the normal distribution: unknown mean, known precision

*Blog post
2023
Bayesian statistics
Uses R code
I want to write a paper about the hedging hyperprior. I need to work out some simple examples first. Here is an example involving the normal distribution.
Feb 28, 2023

 

The Imminent Danger of A.I. Is One We’re Not Talking About

*Recommendation
2023
Data science
While there have been recent discussions about Chat GPT and other Artificial Intelligence systems behaving badly, this author cites more important questions: Who will…
Feb 27, 2023

 

Using work resources on outside consulting

*Blog post
2023
Human side of statistics
Dear Professor Mean, I am looking at a post-retirement business venture as a solo statistical consultant. I would wind down the hours at my current job while I build up my…
Feb 27, 2023

 

Early pages on micro-arrays

*Blog post
2023
Genomic analysis
Back around 1998 through about 2004, I tried my best to understand how to manage data from a micro-array experiment and how to analyze it properly. I started some web pages…
Feb 21, 2023

 

Confirmation bias as a misfire of normal Bayesian reasoning

*Recommendation
2023
Bayesian statistics
Critical appraisal
A brief, but interesting argument that confirmation bias is just an example of applying an informative prior. This is an argument that has been made before and one that I…
Feb 18, 2023

 

Beware the man of one study

*Recommendation
2023
Systematic overviews
This blog post starts with a quote from Thomas Aquinas, “Beware the man of one book” and updates it to arguments relying on peer-reviewed studies. He spends a fair amount of…
Feb 18, 2023

 

A critique of data sharing practices

*Blog post
2023
Teaching resources
I attended a panel discussion on data sharing practices in peer-reviewed articles. The major focus was on papers that stated “Data available upon request.” This statement is…
Feb 17, 2023

 

Special issue on teaching reproducibility

*Recommendation
2023
Teaching resources
The Journal of Statistics and Data Science Education has a special issue on teaching reproducibility. I haven’t read the whole issue, but the articles I have read are…
Jan 19, 2023

 

Essential Statistics with R and Python

*Recommendation
2023
Teaching resources
This book has two advantages. First, it is freely downloadable. Second, it uses both R and Python code to solve the problems. The book covers most of the basic statistics…
Jan 9, 2023

 

Download statistics of R packages

*Recommendation
2023
R software
Both CRAN and Bioconductor track the number of downloads for their packages over time. You can access these statistics for any of the packages you are interested in. A large…
Jan 5, 2023

 

Writing a scope of work

*Recommendation
2023
R software
I attended a great panel discussion at the Conference on Statistical Practice on how to write a scope of work. Most of the panelists cited Peterson et al 2022 in their…
Jan 5, 2023

My boxplot shows a box but no whiskers

*Blog post
2022
Graphical display
One of my favorite graphs is the box plot. It is a visualization of a five number summary. Those five numbers are minimum, 25th percentile, median (aka the 50th percentile)…
Dec 15, 2022
Steve Simon

 

Troubleshooting tips when you have errors in your SAS code

*Blog post
2022
SAS software
One of my SAS students wanted advice about how to troubleshoot. It’s not an easy question to answer and depends a lot on the type of problem you encounter. Here are a few…
Dec 14, 2022
Steve Simon

 

Naming your consulting company

*Blog post
2022
Human side of statistics
Someone asked about what to name their new statistical consulting company. They were worried about choosing a name that was too similar to another company out there. This…
Dec 12, 2022
Steve Simon

 

What it means when your variable names are numbers

*Blog post
2022
SAS software
More than one of my students had trouble importing a text file and ended up with numbers as variable names. Here’s what went wrong.
Dec 12, 2022
Steve Simon

 

Statement order in SAS programs

*Blog post
2022
SAS software
Someone asked about deciding how to know what order to put SAS programming statements in. I answered that you just need to use a bit of common sense.
Dec 12, 2022
Steve Simon

 

Modern books on mathematical statistics

*Blog post
2022
Teaching resources
Someone asked for some recommendations for books on mathematical statistics that take a more modern and applied approach. I am not at all familiar with this, so I…
Dec 10, 2022
Steve Simon

 

D3, Data-Driven Documents

*Recommendation
2022
Graphical display
D3 is a powerful system for visualization with a small footprint. This page gives an overview of D3 and some very basic tutorials.
Nov 30, 2022

Schoenfeld residuals

*Blog post
2022
Rmarkdown code
Survival analysis
There are several different types of residuals in a Cox proportional hazards model. One of them is the Schoenfeld residuals. They are used to test the proportional hazards…
Nov 30, 2022
Steve Simon

 

And finally I would like to thank my cat

*Quotation
2022
Writing research papers
Last Friday’s footnote about unusual dissertation acknowledgments prompted some of you to share others, and I noticed a theme: Pets! Hillary Anger Elfenbein, a business…
Nov 19, 2022

 

Machine learning resources from a seminar by Shuhao Cao

*Blog post
2022
Data science
I attended an interesting seminar presented by Shuhao Cao, a new faculty member in Mathematics and Statistics at UMKC. Almost all of the talk was over my head, but I did…
Nov 12, 2022
Steve Simon

 

The POSIX time standard

*Blog post
2022
Data science
Rmarkdown code
I thought I understood everything about how computers represent time, but apparently not. There is an important time standard, POSIX time, that I was not all that aware of.…
Nov 12, 2022
Steve Simon

 

Using regular expressions in SAS

*Recommendation
2022
SAS software
Regular expressions are a powerful way to identify and manipulate string data. SAS implements regular expressions through through the prxparse, prxmatch, prxsubstr, prxposn…
Nov 6, 2022

 

Blogdown equations

*Blog post
2022
Data management
I write my updated blog using a mix of Markdown (*.md) and R Markdown (*.Rmd) files. If the blog post has R code in it, I use R Markdown. But I am finding that equations can…
Nov 3, 2022
Steve Simon

 

Confusion caused by multiple date formats

*Blog post
2022
Data management
If you are given data that includes dates, expect confusion. Dates can be represented in many different ways.
Oct 30, 2022
Steve Simon

 

Internal storage format for dates

*Blog post
2022
Data management
If you are given data that includes dates, expect confusion. Dates can be represented in many different ways.
Oct 30, 2022
Steve Simon

 

Missing value functions

*Blog post
2022
Data management
Comparisons involving missing values are tricky.
Oct 27, 2022
Steve Simon

 

Missing value hell

*Blog post
2022
Data management
There’s no mincing words here. Missing values are hell for every statistician. Here are a few examples.
Oct 23, 2022
Steve Simon

 

Why weighting for iid data is inefficient

*Blog post
2022
Statistical theory
Usually, you use weighting to gain efficiency in a setting where different data points have different variances. But if the variances are equal, such as in an independent…
Sep 26, 2022
Steve Simon

 

Recommendation for the oral presentation at a thesis defense

*Blog post
2022
Human side of statistics
I got a question about what to prepare for the presentation that a student was going to do for a thesis defense.
Sep 8, 2022
Steve Simon

 

How can cloud computing help improve equity in the classroom and data science research

*Blog post
2022
Software engineering
I attended a webinar presented by Dartmouth University, the ninth in a series of talks in the Summer 2022 Data Science and AI Webinar Series. The speaker, Mohammad…
Aug 26, 2022
Steve Simon

 

OpenIntro datasets

*Recommendation
2022
Datasets
OpenIntro is a site that publishes several open source textbooks. This page on their site provides a compilation of datasets from a variety of sources that can be used with…
Aug 26, 2022

 

Recommendations for qualitative research in five categories

*Recommendation
2022
SAS software
Software engineering
The first in a series of tweets that lists a few resources for five (nine?) areas of qualitative research. These areas are: case study, ethnography, coding, interviewing…
Aug 23, 2022

 

List of datasets for machine-learning research

*Recommendation
2022
Datasets
A list of hundreds of datasets: some are numeric, some are labelled images or sounds, that can be used to test various machine learning algorithms.
Jul 13, 2022

 

Different parameterizations for one factor ANOVA

*Blog post
2022
Analysis of variance
Rmarkdown code
I’m trying to understand some of the basics of contrasts in analysis of variance. In particular, I want to figure out some alternative parameterizations of the coefficients…
Jul 6, 2022
Steve Simon

 

A simple visual alternative to all pairwise comparisons

*Blog post
2022
Analysis of means
Rmarkdown graphs
The classic follow-up to a significant F test in analysis of variance is examining all pairwise differences in means. It’s great for many problems, but sometimes you may not…
Jul 4, 2022
Steve Simon

Dunnett’s test

*Blog post
2022
Analysis of means
Rmarkdown graphs
I’m a big fan of Analysis of Variance (ANOVA). I use it all the time. I learn a lot from it. But sometimes it doesn’t test the hypothesis I need.
Jul 4, 2022
Steve Simon

 

Scientific American article on the bootstrap

*Recommendation
2022
Statistical computing
The bootstrap is a computational approach that allows you to create confidence intervals and hypothesis tests in a wide range of setting where normality or asymptotic…
Jun 29, 2022

 

Git cartoon from xkcd

*Recommendation
2022
Statistical computing
I use git for version control, but I have to admit that I don’t understand most of its commands. This cartoon satirizes my perspective, which apparently is common among many…
Jun 29, 2022

 

Scientific American article on the bootstrap

*Recommendation
2022
Survival analysis
This is a fairly comprehensive review of the variety of approaches you can use to model recurrent events in a time-to-event model. The authors share some code as well. You…
Jun 29, 2022

 

Interesting links from the UseR 2022 conference

*Blog post
2022
Teaching resources
I am attending the UserR conference this week. It is a virtual format, which has its advantages and disadvantages. I want to track a variety of links that I found from the…
Jun 21, 2022
Steve Simon

 

Selecting a Data Repository

*Recommendation
2022
Data sharing
The National Institutes of Health encourages researchers that it funds to share their data, subject to various privacy conditions. If you do share your data, NIH has a lot…
Jun 20, 2022

 

A Taste of Observable

*Recommendation
2022
Graphical display
I was researching quarto, a successor to RMarkdown, and learned that it supports something called Observable. I have a difficult time characterizing Observable. It appears…
Jun 13, 2022

 

With Quarto Coming, is R Markdown Going Away? No.

*Recommendation
2022
R software
I attended a talk where the presenter used quarto rather than RMarkdown to create their slides. I had never heard about quarto, so I did some searching. There are a lot of…
Jun 13, 2022

 

Zoom security options

*Blog post
2022
Teaching resources
I use Zoom for a variety of meetings, webinars, etc. Back in May 2022, I got Zoombombed. Several neo-nazis joined a Zoom meeting I was hosting and raised havoc. With help…
Jun 11, 2022
Steve Simon

 

Behind GitHub’s new authentication token formats

*Recommendation
2022
Epidemiology
An article by Gary Taubes in 1995 made a big splash by alleging that Epidemiology has met its limits because the effect sizes that they were looking for in recent years were…
Jun 10, 2022

 

SAS Tutorial | How to use Git with SAS

*Recommendation
2022
SAS software
Software engineering
I attended a very nice talk by Chris Hemedinger about using git with SAS. Git is a program that uses version control to manage a programming project. It is integrated nicely…
Jun 10, 2022

 

Behind GitHub’s new authentication token formats

*Recommendation
2022
Software engineering
I only have a vague idea what an authentication token is, but I should probably learn more. I got a notice from GitHub that I was using an old authentication token and…
Jun 8, 2022

 

Deploy Now

*Recommendation
2022
Website details
I am upgrading and consolidating my website and blog to blogdown, an R package based on Hugo. My website is currently hosted by Ionos (formerly 1-and-1). Ionos is offering a…
Jun 7, 2022

 

Understanding Random Forest

*Recommendation
2022
Website details
This is a nice non-technical explanation of how the Random Forest model works and why it is so effective.
Jun 7, 2022

 

Library Research Tutorials

*Recommendation
2022
Writing research papers
If you plan on writing a serious research paper, you should work closely with a librarian, who can help in a variety of different areas. The librarians at UMKC have prepared…
Jun 1, 2022

 

Testing d3

*Blog post
2022
Graphical display
Incomplete page
I am interested in developing some visualization applications using d3. You can run d3 from within R Markdown.
Jun 1, 2022
Steve Simon

 

Definition, Adverse reaction

*Definitions
2022
Clinical trials
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Alpha

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Beta

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Binomial distribution

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Binomial mean

*Definitions
2022
Probability concepts
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Binomial probability

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Boxplot

*Definitions
2022
Graphical display
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May 28, 2022
Steve Simon

 

Definition, Case-control study

*Definitions
2022
Research design
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Categorical data

*Definitions
2022
Measurement scales
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May 28, 2022
Steve Simon

 

Definition, Cohort study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Common cause variation

*Definitions
2022
Quality improvement
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May 28, 2022
Steve Simon

 

Definition, Conditional probability

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Continuous data

*Definitions
2022
Measurement scales
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May 28, 2022
Steve Simon

 

Definition, Control chart

*Definitions
2022
Quality improvement
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Convenience sample

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Correlation coefficient

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Cross sectional study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Crossover study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Decision rule

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Dependent variable

*Definitions
2022
Inferential statistics
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May 28, 2022
Steve Simon

 

Definition, Descriptive study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Diagnostic test

*Definitions
2022
Diagnostic testing
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May 28, 2022
Steve Simon

 

Definition, Entropy

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Experimental design

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Fagan nomogram

*Definitions
2022
Diagnostic testing
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May 28, 2022
Steve Simon

 

Definition, Geometric mean

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Independence

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Independent variable

*Definitions
2022
Inferential statistics
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May 28, 2022
Steve Simon

 

Definition, Inferential statistics

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Interquartile range

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Interval data

*Definitions
2022
Measurement scales
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May 28, 2022
Steve Simon

 

Definition, Kappa

*Definitions
2022
Descriptive statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Likelihood ratio

*Definitions
2022
Diagnostic testing
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May 28, 2022
Steve Simon

 

Definition, Longitudinal study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Mann-Whitney-Wilcoxon test

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Mean

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Median

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Mode

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Mosaic plot

*Definitions
2022
Graphical display
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May 28, 2022
Steve Simon

 

Definition, Negative predictive value

*Definitions
2022
Diagnostic testing
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May 28, 2022
Steve Simon

 

Definition, Nominal data

*Definitions
2022
Measurement scales
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May 28, 2022
Steve Simon

 

Definition, Observational study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Odds

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Odds ratio

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Ordinal data

*Definitions
2022
Measurement scales
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May 28, 2022
Steve Simon

 

Definition, Parallel groups study

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, Parameter

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Percentiles

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Phi coefficient

*Definitions
2022
Descriptive statistics
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May 28, 2022
Steve Simon

 

Definition, Binomial probability

*Definitions
2022
Descriptive statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Poisson distribution

*Definitions
2022
Probability concepts
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May 28, 2022
Steve Simon

 

Definition, Population

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Positive predictive value

*Definitions
2022
Diagnostic testing
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May 28, 2022
Steve Simon

 

Definition, Purposive sample

*Definitions
2022
Research design
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May 28, 2022
Steve Simon

 

Definition, P-value

*Definitions
2022
Hypothesis testing
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May 28, 2022
Steve Simon

 

Definition, Qualitative study

*Definitions
2022
Research design
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Quota sample

*Definitions
2022
Research design
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Random sample

*Definitions
2022
Research design
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Range

*Definitions
2022
Descriptive statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Ratio data

*Definitions
2022
Measurement scales
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Retrospective study

*Definitions
2022
Research design
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Sample

*Definitions
2022
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Sensitivity

*Definitions
2022
Diagnostic testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Special cause variation

*Definitions
2022
Quality improvement
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Specificity

*Definitions
2022
Diagnostic testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Standard deviation

*Definitions
2022
Descriptive statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Standard error

*Definitions
2022
Descriptive statistics
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Statistic

*Definitions
2022
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Stem and leaf diagram

*Definitions
2022
Graphical display
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, t-statistic

*Definitions
2022
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Type I error

*Definitions
2022
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Type II error

*Definitions
2022
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

Definition, Weighted mean

*Definitions
2022
Descriptive statistic
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 28, 2022
Steve Simon

 

My writing goals for Summer 2022

*Blog post
2022
Website details
I did not make much progress on updating my website over the past few months. My teaching load was heavier than what I was used to, and I had other writing goals for various…
May 24, 2022

 

Improving Representation in Clinical Trials and Research

*Recommendation
2022
Health disparities
This report summarizes the work of a task on diverse representation in clinical research. It summarizes the problems with under-representation of minorities in clinical…
May 23, 2022
Steve Simon

 

Getting started with SAS On Demand for Academics

*Blog post
2022
SAS software
Teaching a class in SAS is tricky because some students do not have easy access to the SAS software. SAS is a commercial product and the price that you would have to pay is…
May 21, 2022
Steve Simon

 

IPUMS Health Surveys

*Recommendation
2022
Data science
IPUMS is a project that stores and harmonizes data from various public sources. This particular site harmonizes data from the National Health Interview Survey and the…
May 16, 2022
Steve Simon

 

Using ML for complex survey data

*Recommendation
2022
Data science
Complex surveys
{80%}
May 16, 2022
Steve Simon

 

Preparing raw clinical data for publication

*Recommendation
2022
Data sharing
Here are some practical suggestions on how to prepare the raw data for inclusion in a peer-reviewed article. The emphasis is on protecting patient confidentiality.
May 15, 2022

 

Whose data set is it anyway?

*Recommendation
2022
Data sharing
Andrew Vickers makes a strong case for the need to share research data for any peer-reviewed publication.
May 15, 2022

 

Using the foreach package

*Recommendation
2022
R software
The foreach package provides an easy way to take advantage of parallel processing within an R program. This vignette shows how to do this with some simple examples.
May 11, 2022
Steve Simon

 

An international multi-centre cohort study of weight loss in overweight cats

*Recommendation
Broken-image-link
2022
Teaching resources
One of my students used an interesting dataset for their final project. It is freely available on the web and might be one I would use in future classes.
May 8, 2022

 

Creative Commons

*Recommendation
2022
Open source
The most commonly used open source licenses for journal articles are those developed by a volunteer organization, Creative Commons. They provide options that can insure that…
May 8, 2022

 

What Influences Saturation? Estimating Sample Sizes in Focus Group Research

*Recommendation
2022
Qualitative research
Sample size justification
One of my students shared this paper with me. It talks about when you should expect to see saturation in a focus group study. It uses some hard date to answer this question.
May 8, 2022

 

Open Source Initiative, Licenses and Standards

*Recommendation
2022
Open source
There are a variety of open source licenses that are used for software. This site lists some of the most popular licenses and answers some common questions.
May 8, 2022

 

What Influences Saturation? Estimating Sample Sizes in Focus Group Research

*Recommendation
2022
Qualitative research
Sample size justification
One of my students shared this paper with me. It talks about when you should expect to see saturation in a focus group study. It uses some hard date to answer this question.
May 8, 2022

 

The Use and Interpretation of Competing Risks Regression Models

*Recommendation
2022
Data science
This is a nice overview of competing risks that draws important distinctions from the Cox proportional hazards model.
Apr 22, 2022

 

Interesting resources discovered during IDAD 2022

*Blog post
2022
Teaching resources
During the talks at the Innovations in Design Analysis and Dissemination (IDAD): Frontiers in Biostatistics & Data Science in 2022, I took a peek at various website and…
Apr 21, 2022
Steve Simon

 

Different creatures in the R zoo

*Blog post
2022
R software
Rmarkdown code
R has a variety of ways of storing information. It is a hodge-podge of different things. I’ll call these “things” creatures, though that is probably not the right word. Let…
Apr 14, 2022
Steve Simon

 

Interesting resources discovered during Nexus Informatics 2022

*Blog post
2022
Informatics
During the talks at the Nexus Informatics conference of 2022, I took a peek at various website and articles. These were either ones that the speakers mentioned or ones I…
Apr 9, 2022
Steve Simon

 

A quick overview of various git verbs

*Blog post
2022
Software engineering
I am a beginner in using version control, even though I have relied on it for several years now. I’m beginning to encourage others to use version control with joint projects…
Mar 26, 2022
Steve Simon

 

IBM Watson: Why Is Healthcare AI So Tough?

*Recommendation
2022
Data science
IBM Watson is a supercomputer that has handled some difficult problems that are diffuse and poorly defined. In particular, it was able to compete in a general knowledge…
Mar 8, 2022

 

There’s a Smarter Way to Think About the Under-5 Vaccine.

*Recommendation
2022
Bayesian statistics
A statistician and parent of three young children laments a recent delay in approval of a COVID vaccine for children under the age of 5. He argues that the FDA emphasis on…
Mar 7, 2022

 

Confusion about observational designs

*Blog post
2022
Observational studies
In one of my lectures on Clinical Research Methodology, I point out how easy it is to confuse various types of observational studies for one another. This is usually because…
Feb 26, 2022

 

Scientific writing, Strategies and tools for students and advisors

*Recommendation
2022
Writing research papers
A guide from the beginning to the end of writing a scientific paper.
Feb 11, 2022
Steve Simon

 

A Reviewer’s Quick Guide to Assessing Open Datasets

*Recommendation
2022
Open data
A brief guide for peer reviewers who have to look at the datasets being shared as part of a proposed publication.
Feb 5, 2022
Steve Simon

 

The ASCCR Frame for Learning Essential Collaboration Skills

*Blog post
2022
Human side of statistics
Incomplete page
Consulting on statistical issues with a non-statistician is an art. Eric Vance and Heather Smith outline an effective process described by an acronym ASCCR (Attitude…
Feb 1, 2022
Steve Simon

 

Using change scores

*Blog post
2022
Risk adjustment
Incomplete page
On the ASA Connect Digest, someone was asking about references discussing the practice of using change scores as the outcome variable with the baseline variable as a…
Feb 1, 2022
Steve Simon

 

How Big of a Sample Size do you need for Factor Analysis

*Recommendation
2022
Sample size justification
Determining an appropriate sample size for Factor Analysis is tricky. You can’t easily use a power calculation because Factor Analysis ordinarily does not have a traditional…
Jan 17, 2022

 

International Academy for Quality

*Recommendation
2022
Quality improvement
An elite organization devoted to the promotion of quality initiatives in academia and industry. Note the link to the quality manifesto for the 21st Century.
Jan 12, 2022

 

RNA-Seq Analysis. Methods, Applications and Challenges

*Recommendation
2022
Genomics analysis
This editorial provides a broad overview of a special issue on RNA-Seq analysis, a new approach for quantifying gene expression levels.
Jan 12, 2022

Mapping latitude and longitude

*Blog post
2022
Geocoding
I’m trying to understand some of the basics of mapping and found an interesting example on [this website]
Jan 6, 2022
Steve Simon

 

Philosophy emergency

*Recommendation
2022
Critical appraisal
When I teach “Clinical Research Methodology,” I have to discuss the philosophical foundations of research. I am not a philosopher and have just a limited understanding of…
Jan 3, 2022

 

Progress on my website through the end of 2021

*Blog post
2022
Website details
I spent much of Christmas break updating files from the year 2007. This was one of my most productive years. I developed presentations on children in research, open access…
Jan 2, 2022

 

Federated Learning and Privacy

*Recommendation
2021
Data science
This article lays out the general principles of federated learning, a decentralized and privacy protecting approach to statistical modeling.
Dec 30, 2021

 

Uncovering Truths With Missing Data

*Recommendation
2021
Data quality
The U.S. provides a rating system for nursing homes, but there are serious flaws in how this data is collected. In particular, many problems uncovered during government…
Dec 30, 2021

 

Why p-values are not measures of evidence

*Recommendation
2021
Hypothesis testing
There are lots of criticisms of p-values, and while I don’t agree with all of them, it is important to understand these criticisms. This article discusses the definition of…
Dec 18, 2021

 

COSMIN methodology for evaluating the content validity of patient-reported outcome measures: a Delphi study

*Recommendation
2021
Measuring agreement
This paper provides a nice checklist of itmes you should look for in a study establishing content validity ofr a patient-reported outcome measure.
Dec 14, 2021

 

Health Measurement Scales: A Practical Guide to Their Development and Use

*Recommendation
2021
Measuring agreement
A nice comprehensive guide to the development of reliable and valid measurement scales in health care research. It is in its fifth edition; the version in my library is the…
Dec 14, 2021

Overfitting example using hurricane frequencies

*Blog post
2021
Generalized linear model
Rmarkdown graphs
Overfitting occurs when a statistical model is too complex for the amount of data that it is based on. The summary statistics on the data itself appear to be quite good, but…
Dec 11, 2021
Steve Simon

 

Dataset recommendations from the Journal of Statistics Education

*Blog post
2021
Datasets
Teaching resources
The Journal of Statistics Education (now called the Journal of Statistics and Data Science Education) maintains an archive of interesting datasets. The data documentation is…
Dec 1, 2021

 

Dataset recommendations from statlib

*Blog post
2021
Datasets
Teaching resources
A very old resource on the Internet with interesting datasets is statlib. The quality of the documentation is a bit uneven and some of the datasets are too simple to be used…
Dec 1, 2021

 

Joke about the dangers of extrapolation

*Blog post
2021
Linear regressioN
There’s a joke I stole from the Internet, which you can find all over the place (here, here, and here). It is a humorous way of warning about the dangers of extrapolating…
Nov 27, 2021

 

Big Deal for Open Access

*Recommendation
2021
Writing research papers
There is a lot of controversy about open access publishing and the University of California system inserted itself in the middle of the controversy when it canceled…
Nov 27, 2021

 

An overview of the National Health and Nutrition Examination Survey

*Blog post
2021
Secondary data analysis
The National Health and Nutrition Examination Survey (NHANES) is a large scale survey conducted by the Centers for Disease Control and Prevention (CDC). It uses a complex…
Nov 19, 2021

 

Simply Statistics blog

*Recommendation
2021
Graphical display
This is a nice professionally designed blog with no advertisements. The posts are fairly basic and accessible.
Nov 18, 2021

 

How many pages do I have in my website?

*Blog post
2021
Website details
I am updating my website to a new format, and I want to keep track of how many pages have already been updated and how many still need to be updated. It’s tricky to get an…
Nov 16, 2021

 

Data Work. A Jargon-Free Guide to Managing Teams

*Recommendation
2021
Human side of statistics
We get a lot of interesting people who show up at the Kansas City R User Group meetings. Taylor Rodgers is one of them. He is doing a lot of interesting work about how data…
Nov 13, 2021

 

Talk Stats

*Recommendation
2021
Teaching resources
A wide range of questions from basic to advanced about Statistics, Probability, and Statistical Software.
Nov 11, 2021

 

History of Teacup Giraffes

*Recommendation
2021
R software
Teaching resources
A very basic introduction to the R programming language.
Nov 11, 2021

 

We Are in Need of Data Ethics Now

*Recommendation
2021
Ethics in research
Craig S. Mullins. We Are in Need of Data Ethics Now. Database trends and applicaitons, 2018-07-02. Available in html format. Approximately 1,400 words.
Nov 2, 2021

Basics of cubic spline models

*Recommendation
2021
Linear regression
Rmarkdown graphs
Suppose you have some data where you suspect the behavior differs for x=1 to 5, x=6 to 10, x=11 to 15, and x=16 to 20.
Nov 1, 2021
Steve Simon

Test diagrams

*Blog post
2021
Graphical display
Rmarkdown graphs
An earlier version of this page was published on new.pmean.com.
Oct 30, 2021
Steve Simon

 

The Integration of the Humanities and Arts with Sciences, Engineering, and Medicine in Higher Education

*Recommendation
2021
Teaching resources
This report was recommended at a webinar I attended. I have not read the report yet, but the webinar mentioned several interesting and surprising ways that hihger education…
Oct 29, 2021

 

VALUE Rubrics

*Recommendation
2021
Teaching resources
VALUE is an acronym for Valid Assessment of Learning in Undergraduate Education. This site provides rubrics for intellectual skills such as critical thinking and problem…
Oct 29, 2021

Very simple spline models

*Recommendation
2021
Linear regression
Rmarkdown graphs
Suppose you want to fit a function that is flat from x=a to x=b and which declines linearly from x=b to x=c.
Oct 29, 2021
Steve Simon

The dark side of big data

*Blog post
2021
Data science
Incomplete page
Rmarkdown graphs
Steve Simon
Oct 28, 2021

 

What’s all this reading about then

*Recommendation
2021
Writing research papers
What does it mean to review the literature. This article digs into that question and offers a wealth of additional resources.
Oct 26, 2021

 

How to Share Your Research

*Recommendation
2021
Writing research papers
THis article covers new changes in the publication process, including pre-prints and trial registration.
Oct 26, 2021

 

10 ingredients for a successful supervisor/PhD student relationship

*Recommendation
2021
Human side of statistics
It’s important to provide guidance to a PhD candidate, and finding the right balance is important.
Oct 23, 2021

Survival of the best fit

*Recommendation
2021
Data science
http://www.pmean.com/new-images/21/best-fit-simulation-01.png)
Oct 22, 2021

 

Ethical data science

*Recommendation
2021
Ethics in research
Data science
A nice article talking about the importance of interpretability in data science.
Oct 21, 2021

 

Lead assessments in the NHANES survey

*Recommendation
2021
Secondary data analysis
Here are some resources on the CDC website about NHANES, with special attention to lead assessments.
Oct 19, 2021

Diagnostics for a generalized linear model

*Blog post
2021
Generalized linear model
Incomplete page
Rmarkdown graphs
There are a broad range of diagnostic methods (mostly graphical) that can help you decide from among a dizzying array of alternative models for count data. The most…
Oct 18, 2021
Steve Simon

 

Journals Must Stop Exploiting Research for Profits

*Recommendation
2021
writing research papers
A harshly critical opinion piece about journals that expect free work from writers, editors, and reviewers, but then charges readers for access.
Oct 18, 2021

 

First steps with blogdown

*Blog post
2021
Website details
Rmarkdown code
I am in the process of merging my website, written from 1999 to 2012 with my blog, which I started around 2012. I am using blogdown, an R package that creates a website from…
Oct 9, 2021
Steve Simon

 

Progress in evidence-based medicine

*Recommendation
2021
Health disparities
A nice summary of the changes (mostly improvements) in Evidence Based Medicine (EBM) over the past 25 years. It was written by two of the pioneers in EBM.
Oct 7, 2021

 

Health equity tourists: How white scholars are colonizing research on health disparities

*Recommendation
2021
Health disparities
This article raises a difficult topic. While it is good that more white researchers are interested in health disparities research recently, some newcomers have marginalized…
Sep 29, 2021

Reading information from the American Community Survey into R

*Recommendation
2021
Incomplete page
Rmarkdown graphs
Secondary data
Here is a simple example of how to read data from the American Community Survey into R.
Sep 29, 2021

 

LaTeX Math in Markdown

*Recommendation
2021
Website details
I am having difficulty getting my website converted to blogdown. The latest problem is that all my math equations are not rendering properly. Yihui Xie suggests some reasons…
Sep 28, 2021

 

UMKC Faculty Researcher Award

*Blog post
2021
Professional details
The UMKC School of Medicine has yearly awards that it hands out to faculty including a faculty researcher award. The awards allow for self-nomination, so I thought “Why not?”
Sep 28, 2021

 

Data Mining, Discovery and Exploration

*Recommendation
2021
Data mining
This girhub repository has all the PowerPoint slides, handouts, and Python notebooks for a data mining course taught by Steve Elston of Harvard University. It is oriented…
Sep 22, 2021
Steve Simon

 

Nursing Research, Step by Step

*Recommendation
2021
Research design
This is a collection of articles (currently only five, but I suspect more will be added over time) that were published in the American Journal of Nursing. They cover some of…
Sep 22, 2021
Steve Simon

 

Happy Git and GitHub for the useR

*Recommendation
2021
R software
Software engineering
I have found that version control using git to be an integral part of my workflow. This website is an introduction of how to use git with R.
Sep 21, 2021
Steve Simon

 

Direct standardization of mortality rates

*Blog post
2021
Epidemiology
Incomplete pages
Rmarkdown graphs
Mortality rates in different regions of the United States between different countries are dependent on the demographic distributions. Differences in the age distribution can…
Sep 20, 2021
Steve Simon

Deviance in a generalized linear model

*Blog post
2021
Generalized linear model
Rmarkdown graphs
Deviance is a measure computed for generalized linear models that can help you decide between two competing models. It is somewhat analogous to residual sums of squares in…
Sep 20, 2021
Steve Simon

 

Quasi-likelihood models

*Blog post
2021
Generalized linear model
Rmarkdown graphs
With the generalized linear model, you have the option of choosing a model that works well with a variety of different distributions (normal, Poisson, Gamma, etc.). But you…
Sep 20, 2021
Steve Simon

 

Zero-inflated models

*Blog post
2021
Generalized linear model
Incomplete page
Rmarkdown graphs
In models of counts, zeros represent a special case. Often there is more than one reason why you might observe a zero count, and you might want to model this probability…
Sep 20, 2021
Steve Simon

Working with negative binomial regression

*Blog post
2021
Probability distributions
Generalized linear model
Rmarkdown graphs
The negative binomial distribution is similar to the Poisson distribution, but it offers a bit more flexibility. This page will review some basic properties of the negative…
Aug 30, 2021
Steve Simon

Working with the Poisson distribution

*Blog post
2021
Incomplete page
Probability distributions
Rmarkdown graphs
Many statistics, such as mortality statistics, are based on fundamental counting processes. If you want to understand these processes, you should start by trying to…
Aug 30, 2021
Steve Simon

 

Working with Poisson regression

*Blog post
2021
Probability distributions
Rmarkdown graphs
Poisson regression is a statistical model under the large umbrella of generalized linear models. I want to explain how Poisson regression works. I also will show and…
Aug 30, 2021
Steve Simon

 

Shape-Restricted Regression Splines with R Package splines2

*Recommendation
2021
Linear regression
Splines allow you to fit an almost infinitely flexible number of nonlinear curves, but sometimes you want to place restrictions, such as monotonicity or periodicity on those…
Aug 30, 2021

 

Show me the data

*Recommendation
2021
Critical appraisal
Inadequate data on the COVID-19 pandemic has hindered our ability to make the right decisions about prevention and treatment.
Aug 27, 2021

 

Real-world String Comparison

*Recommendation
2021
Statistical computing
A nice article that talks about the problems with comparing strings when multi-byte Unicode characters are used.
Aug 25, 2021

 

Asking great questions

*Recommendation
2021
Human side of statistics
Eric Vance has done a lot of work about improving the process of statistical consulting. This talk was presented at the 2021 Joint Statistics Meetings and explained that…
Aug 13, 2021

 

Two resources for getting started in statistical consulting

*Recommendation
2021
Human side of statistics
While looking for some materials on my site, I found a couple of things that others had written about getting starting in the business of statistical consulting.
Aug 13, 2021

 

Efforts of biostatisticians in research

*Recommendation
2021
Human side of statistics
I attended a talk on the special issues facing biostatisticians in academic positions. The speaker shared three interesting documents about how to evaluate statistical…
Aug 13, 2021

 

The Vancouver Recommendations

*Recommendation
2021
Writing research papers
This is a consensus document created by a group of journal editors who met in Vancouver in 1978. This has been updated regularly. It covers authorship guidelines on…
Aug 13, 2021

 

Speaking R

*Recommendation
2021
R software
Teaching resources
An hour long video, but worth watching for anyone who teaches programming, but especially anyone who teaches R. The general thesis is that you should speak the code as you…
Aug 12, 2021

 

The Precis-2 toolkit

*Recommendation
2021
Research design
A nice guide for assessing the degree to which a clinical trial is pragmatic. It uses a nine item scale that is intuitive and easy to apply. There is also a website that…
Aug 11, 2021

 

R Open Science

*Recommendation
2021
R software
R OPen Science is a team effort to develop a systematic process to develop and test R packages. The team has a web site, a book, and a software review system.
Aug 11, 2021

 

Resources for spatial statistics

*Recommendation
2021
R software
I attended a talk on recent developments in spatial statistics and while most of the talk was over my head, I did not some resources in the introduction that might be…
Aug 11, 2021

 

Resources for AI Fairness

*Recommendation
2021
Data science
The Joint Statistics Meetings had a great talk on Fairness in Artifical Intelligence (AI). The speaker, Sherrie Rose, documented instances where AI has had a discriminatory…
Aug 9, 2021

 

Developing and Maintaining Open Source Resources for Statistics and Data Science Education

*Recommendation
2021
Teaching resources
This website provides the slides and other resources associated with a session at the 2021 Joint Statistics Meetings on open source education resources.
Aug 9, 2021

 

Julia for Statistics and Data Science

*Recommendation
2021
Julia programming
Doug Bates gave an excellent talk at the 2021 Joint Statistics Meetings about Julia, a new programming language that tries (and to a large extent succeeds) to be both…
Aug 8, 2021

 

Special Issue on Statistical Practice

*Recommendation
2021
Writing research papers
The journal STAT (not the medical term for immediately, but rather an abbreviation of the word, Statistics) will be calling for a special issue on Statistical Practice. The…
Aug 8, 2021

 

Learning more about SAS

*Blog post
2021
SAS software
A student in my Introduction to SAS class (MEDB 5507) asked a question that was difficult to answer, but also important to answer. The student wanted to know “a good…
Aug 1, 2021

 

How to Choose the Journal That’s Right for Your Study

*Recommendation
2021
Writing research papers
An easy to read guide on picking the right journal to send your publication to.
Jul 27, 2021

 

Kaggle, 80 cereals

*Recommendation
2021
Datasets
I’m always on the lookout for simple but interesting datasets. This one provides nutritional informaton on 80 different cereal products.
Jul 27, 2021

 

Broadcom in talks to buy SAS for as much as $20B

*Recommendation
2021
SAS software
SAS Institute is a privately held company and the two owners are both getting old. So this report about a possible purchase of SAS by an outside group is an interesting…
Jul 19, 2021

 

Cel-Sci CEO tries to spin cancer trial failure into a win

*Recommendation
2021
Human side of Statistics
It is unusual for issues like p-value hacking to make it into our court system. It is unpredictable how judges will react to some rather technical arguments..
Jul 19, 2021

 

Introduction to Formulaic

*Recommendation
2021
R software
This R package automates an important part of model building: creating formula objects.
Jul 8, 2021

 

Mapping R functions

*Recommendation
2021
R software
In a large R program, you might lose track of how functions that you wrote relate to one another. This program examines those relationships and produces an adjacency matrix.
Jul 8, 2021

 

Metadata vignette

*Recommendation
2021
R software
Reproducible research
This package has a collection of functions that lets you create information about a dataset in R and store that information as an attribute. This makes it easier for you to…
Jul 8, 2021

 

The obesity wars and the education of a researcher

*Recommendation
2021
Human side of statistics
Some areas of research are quite contentious and when you publish an article that angers advocates on one side or the other of an issue, you may find yourself the talk of…
Jul 8, 2021

 

R Package for Adaptive Clinical Trials

*Recommendation
2021
Bayesian statistics
R software
A nice introduction to a package for group sequential designs using Bayesian methods.
Jul 8, 2021

 

Types of Statistics Papers

*Recommendation
2021
Writing research papers
A humorous cartoon about research topics in Statistics.
Jul 8, 2021

 

R Packages

*Recommendation
2021
R programming
A great resource if you want to develop a package in R. You can buy this book, or read it for free.
Jul 8, 2021

 

Basic Python Resources

*Blog post
2021
Python
I’m trying to learn Python, and a recent short course (Data Scientist’s Workflow: EDA and Statistical Modeling with Python in Jupyter Noteboos workshop, taght by Chris…
Jun 12, 2021

 

Anonymizing ids

*Blog post
2021
Privacy in research
Rmarkdown code
I’m working on a project that might be exempt from IRB review…if I can convert a particular ID code to an anonymous code. The ID codes are an eight digit number. Here’s a…
Jun 10, 2021
Steve Simon

 

Statistical Thinking

*Recommendation
2021
Teaching resources
Frank Harrell is a very opinionated statisticians, and his opinions are almost always on the mark. He’s shaped the discipline of Statistics in many ways over a career that…
Jun 7, 2021

 

S, R, and data science

*Recommendation
2021
R software
John Chambers is one of the creators of the S programming language,a pre-cursor to R. In this article, he describes how both R and S were developed with goal of advancing…
Jun 5, 2021

 

Finally, a proven method to show just how funny I am

*Recommendation
2021
Data science
A satirical look at sentiment analysis–in particular, the use of sentiment analysis to identify “the funniest movies ever made.”
May 31, 2021

 

Songs by Tom Lehrer (1953), Lobachevsky

*Recommendation
2021
Ethics in research
A cute song by famous satirist, Tom Lehrer, on the secret of success in research. Plagiarism!
May 27, 2021

 

Choosing a good chart

*Recommendation
2021
Graphical display
A simple guide for choosing among a variety of different visualization methods. These are mostly basic charts, such as pie charts, histograms, and pie charts. I don’t agree…
May 18, 2021

 

The illusion of predictability. How regression statistics mislead experts

*Recommendation
2021
Human side of statistics
The authors argue that regression models fail to capture important levels of uncertainty needed for economic decisions.
May 18, 2021

 

Reference Collection to push back against Common Statistical Myths

*Recommendation
2021
Teaching resources
There are some commonly used statistical methods (e.g., post hoc power, stepwise regression) which are widely criticized in the Statistics literature. If you run across one…
May 16, 2021

 

An introduction to the Poisson bootstrap

*Recommendation
2021
Bootstrap
An interesting approach to the Bootstrap that can handle big data in a single pass, even if you don’t know the number of observations in the data set or the data is split…
May 10, 2021

 

Downweighting informative prior distributions

*Blog post
2021
Bayesian statistics
There are a variety of approaches to handle informative prior distributions when they disagree sharply with the data. I want to summarize a few papers that present these…
May 7, 2021

 

COMPAS Recidivism Risk Score Data and Analysis

*Recommendation
2021
Data science
The data behind a classic article about algorithmic bias.
Apr 29, 2021

 

Experimental Evaluation of Algorithm-Assisted Human Decision-Making: Application to Pretrial Public Safety Assessment

*Recommendation
2021
Data science
Cutting edge research on algorithms and how they affect human biases.
Apr 29, 2021

 

Alluvial Plots in ggplot2

*Recommendation
2021
Graphical display
Alluvial plots show streams of different colors that show how certain categorical variables interrelate. I am not sure that the graphs are all that effective, but if you…
Apr 28, 2021

 

Changing and modifying a Hugo theme on your R Blogdown site

*Recommendation
2021
Graphical display
A nice very detailed blog post about how to change to a different Hugo theme within blogdown and how to adapt that theme to your special requirements.
Apr 28, 2021

 

Heterogeneity introduced by EHR system implementation in a de-identified data resource from 100 non-affiliated organizations

*Recommendation
2021
Electronic health records
A nice illustration of how chaotic electronic health record data can be when aggregated across a large number of hospitals.
Apr 28, 2021

 

Replication Crisis

*Recommendation
2021
Critical appraisal
This is a review of a book by Stuart Ritchie (Science Fictions: Exposing Fraud, Bais, Negligence, and Hype in Science) that offers a very bleak picture of the world of…
Apr 28, 2021

 

A roadmap to using historical controls in clinical trials

*Recommendation
2021
Graphical display
More and more new drug applications are relying on historical controls, but this must be done carefully. This paper outlines the reasons why you might want to use historical…
Apr 28, 2021

 

Upset plot, the R Graph Gallery

*Recommendation
2021
Graphical display
While Venn diagrams can illustrate how much overlap there is among two or three groups, it becomes more complex when you have a lot more than three groups. The upset plot is…
Apr 28, 2021

 

Police Killings dataset

*Recommendation
2021
Datasets
The data is from 2015, which makes it a bit dated, but this is an interesting dataset with information from a British newspaper, The Guardian, combined with information from…
Apr 23, 2021

 

Amazon scraps secret AI recruiting tool that showed bias against women

*Recommendation
2021
Data science
This is a cautionary article about how machine learning models can lead to unintended discriminatory hiring policies.
Apr 16, 2021

 

Ethical AI: A Framework for Justice

*Recommendation
2021
Data science
This is a cautionary article about how machine learning models can lead to unintended discriminatory hiring policies.
Apr 16, 2021

 

Issues with data and analyses. Errors, underlying themes, and potential solutions

*Recommendation
2021
Critical appraisal
One of my students showed me this paper. It looks at errors in research and tries to array them into a broad set of themes. This is a very ambitious effort and, at first…
Mar 20, 2021

 

Journal of Clinical and Translational Science

*Recommendation
2021
Writing research papers
At a Zoom meeting today, someone mentioned an interesting journal that appears to talk a lot about the research process. It is particularly targeted to medical research and…
Mar 4, 2021

 

Enabling Reproducible Research: Open Licensing for Scientific Innovation

*Recommendation
2021
Data sharing
This paper argues that U.S. Copyright law is a barrier to the sharing of computer code and datasets. She proposes an alternative, the Reproducible Research Standard that…
Feb 15, 2021

 

Papers with code

*Recommendation
2021
Data sharing
This site promotes the sharing of code and data with research publications and offers links to articles that make their code and data freely available.
Feb 15, 2021

 

Census Data Processing 101

*Recommendation
2021
Bureau of the Census
The data collected as part of the decennial U.S. Census comes from a variety of sources and it all needs to be combined. This article provides a simple and easy to follow…
Feb 12, 2021

 

Making the CECPfuns package: my own usable package

*Recommendation
2021
R software
There is a specific structure that you must follow if you want to develop a package in R. This blog post shows a very simple skeleton package with a single R function and…
Feb 12, 2021

 

Final.doc

*Recommendation
2021
Writing research papers
This comic shows the peril of using the word “final” in the name of a file. You will find that you have to make changes that invalidate the finalness of your filename.
Feb 4, 2021

 

The documentation system

*Recommendation
2021
Software engineering
This site was recommended at a webinar I attended on teaching computing skills in a Statistics/Data Science class. Documentation can be split into four different categories…
Jan 26, 2021

 

Help for teaching statistical computing skills

*Blog post
2021
Teaching resources
I attended an interesting webinar on teaching statistical computing skills. The seminar touched on one key paper written in 2010 and a special issue of The Journal of…
Jan 26, 2021

 

An Undergraduate Bayesian Statistics Course

*Blog post
2021
Teaching resources
I attended an interesting webinar on teaching undergraduate Bayesian STatistics courses. Here are some resources I found out about during the webinar. I am putting them here…
Jan 26, 2021

 

Five years of Raspberry Pi clusters

*Recommendation
2021
Cluster computing
I have been interested for quite a while in running a cluster computer using Rapsberry Pis and running software like Spark. Unfortunately, I have been too busy to work on…
Jan 24, 2021

 

How to save RMarkdown output in the results folder

*Blog post
2021
R software
I have a directory structure for most projects that is based on the recommendations in Wilson et al. In particular, I store program code in the src folder and output in the…
Jan 23, 2021

 

How to run SAS inside an RMarkdown file

*Blog post
2021
R software
I create a lot of teaching resources using R Markdown. A question arises about how to incorporate SAS code and output into these teaching resources. I had written earlier…
Jan 23, 2021

 

National Institute of Statistical Sciences

*Recommendation
2021
Teaching resources
The National Institute of Statistical Sciences (NISS) is a consortium of high level researchers in Statistics who develop new methodologies and training solutions. I have…
Jan 21, 2021

 

Smart Tracker

*Recommendation
2021
SQL
I am working with a reasearch team that needs to track a variety of public health outcomes involving testing and vaccination. They are considering a data collection and…
Jan 21, 2021

 

Child documents. Input child document into the main document

*Recommendation
2021
R software
This is part of the documentation for knitr, a package in R. It shows how to include one or more Rmarkdown files inside a master Rmarkdown file.
Jan 11, 2021

 

SASWeave: Literate Programming Using SAS

*Recommendation
2021
SAS software
Russ Lenth has developed a nice system that integrates SAS code and SAS output within a TeX file. This provides a nice way to teach SAS, as you see the SAS code next to the…
Jan 11, 2021

 

Tidy Modeling with R

*Recommendation
2021
Statistical models
Max Kuhn and Julia Slige present a detailed tutorial on some recent advances in R that help you build the best statistical model for your data. This includes the difficult…
Jan 9, 2021

 

I have too many github repositories

*Blog post
2021
Statistical computing
After many presentations at the Kansas City R Users Group, I decided a couple of years ago to do most of my R programming with github as the version control system. Perhaps…
Jan 6, 2021

 

Today’s False Prophets

*Recommendation
2021
Human side of statistics
Ben Chugg article defines a term, cliodynamics, as the effort to predict future political and societal events based on past history. He then explains why this process is…
Jan 4, 2021

 

RCT-DUPLICATE

*Recommendation
2020
Observational studies
Reproducible research
This project is a collaborative effort to find clinical trials used in regulatory decision making and replicate the results using real-world evidence (observational studies…
Dec 21, 2020

 

Precisely the opposite of what we now know to be true

*Quotation
2020
Reproducible research
Dr. Melik: This morning for breakfast he requested something called “wheat germ, organic honey, and tiger’s milk.”
Dec 21, 2020

 

Reproducibility and Replicability in Science

*Recommendation
2020
Reproducible research
This book, produced by the National Academy of Sciences, Engineering, and Medicine, is available for free as a large PDF file, or for purchas as a paperback book or ebook.…
Dec 15, 2020

 

How can you learn R?

*Blog post
2020
R software
I get this question a lot: How do I learn how to use R? I usually mumble something, and feel quite uncomfortable. In fact. It is not easy to learn R on your own. It is not…
Dec 12, 2020

 

COVID-19 open source data sets

*Recommendation
2020
Datasets
Teaching resources
Shuja, J., Alanazi, E., Alasmary, W. et al. COVID-19 open source data sets: a comprehensive survey. Appl Intell (2020). DOI: 10.1007/s10489-020-01862-6. Available in html…
Dec 11, 2020

 

Advice From Blind Teachers on How to Teach Statistics to Blind Students

*Recommendation
2020
Teaching resources
A. Jonathan R. Godfrey and M. Theodor Loots. Advice From Blind Teachers on How to Teach Statistics to Blind Students. Journal of Statistics Education 2015, 23(3). Available…
Dec 7, 2020

 

The tidy tools manifesto

*Recommendation
2020
R software
Hadley Wickham. The tidy tools manifesto. 2019-11-19. Available in html format.
Nov 24, 2020

How I use R Markdown to write research papers

*Blog post
2020
R programming
Rmarkdown graphics
Writing research papers
I joined a writing group at UMKC and am making very good progress on a couple of research papers. The group meets once a week to talk about everyone’s progress and to share…
Nov 21, 2020

 

Advice for a beginner Bayesian

*Blog post
2020
Bayesian statistics
I was asked for some advice about how to get started with Bayesian data analysis. This person had taken a course on this topic, but did not know how to use he learned on a…
Nov 20, 2020

 

Generalized Linear Models

*Recommendation
2020
Datasets
German Rodriguez. Generalized Linear Models. Datasets. Available in html format.
Nov 19, 2020

 

Complementary Log-Log Model for Interval-censored Survival Times

*Recommendation
2020
Survival analysis
SAS Institute. Example 39.11: Complementary Log-Log Model for Interval-censored Survival Times. Available in html format.
Nov 19, 2020

 

Election Maps Are Everywhere. Don’t Let Them Fool You.

*Recommendation
2020
Graphical display
Betsy Mason. Election Maps Are Everywhere. Don’t Let Them Fool You. The New York Times 2020-10-30. Available in html format.
Oct 30, 2020

 

Disappearing Data

*Recommendation
2020
Government statistics
An account of recent events to stop the collection of data that the current administration thinks might hurt some of its efforts to roll back regulations.
Oct 29, 2020

 

The Evolution of Data Science … As I Remember It

*Recommendation
2020
Data science
Charlie Kufs. The Evolution of Data Science … As I Remember It. Stats with Cats blog 2020-10-22. Available in html format.
Oct 22, 2020

 

Making genome data come alive with circos plots

*Recommendation
2020
Graphical display
Maria Nattestad. Making genome data come alive with circos plots. Medium 2017-09-25. Available in html format.
Oct 20, 2020

 

Basic notation for survival or time-to-event analyses

*Blog post
2020
Survival analysis
I got some questions about the notation I use for various functions in survival models and the interpretation of some of these functions.
Oct 12, 2020

 

Bias in Bias Recognition

*Recommendation
2020
Critical appraisal
Qi Wang, Hee J. Jeon. “Bias in Bias Recognition: People View Others but Not Themselves as Biased by Preexisting Beliefs and Social Stigmas.” PsyArXiv, 2020-02-27. Available…
Oct 8, 2020

 

Excel: Why using Microsoft’s tool caused Covid-19 results to be lost

*Recommendation
2020
Data management
Leo Kelion. Excel: Why using Microsoft’s tool caused Covid-19 results to be lost. BBC News 2020-10-06. Available in html format.
Oct 8, 2020

 

How I got started in Evidence-Based Medicine

*Blog post
2020
Evidence-Based Medicine
I am working with a new group looking at early childhood interventions, and they want my advice about a variety of issues related to Evidence-Based Medicine (EBM). Why would…
Oct 1, 2020

 

A New Standard For Publishing On Racial Health Inequities

*Recommendation
2020
Evidence-Based Medicine
Schunemann HJ, Santesso N, Vist GE, et al. Using GRADE in situations of emergencies and urgencies: certainty in evidence and recommendations matters during the COVID-19…
Sep 26, 2020

 

Philosophy of Data Science | Welcome to the Series!

*Recommendation
2020
Data science
Glen Wright Colopy. Philosophy of Data Science | Welcome to the Series! Youtube 2020-09-16. Available in video format.
Sep 26, 2020

 

Stats + Stories

*Recommendation
2020
Podcasts
A. John Bailar. Stats + Stories. Available in html format.
Sep 26, 2020

 

Warning: Physics Envy May be Hazardous to Your Wealth

*Recommendation
2020
Critical appraisal
Lo AW, Mueller MT. Warning: Physics Envy May be Hazardous to Your Wealth! SSRN 2019-03-12. Available in PDF format.
Sep 4, 2020
Steve Simon

 

Research interests

*Blog post
2020
Professional details
I have been asked to present a bit of information about my research interests to the students in the Graduate Research Seminar for the Department of Biomedical and Health…
Sep 1, 2020
Steve Simon

 

Biopharmaceutical Section Offers Advice for ASA Fellow Nomination

*Recommendation
2020
Professional details
Alex Dmitrienko, Ilya Lipkovich, and Paul Gallo. Biopharmaceutical Section Offers Advice for ASA Fellow Nomination. Amstat News 2020-06-01. Available in html format.
Aug 31, 2020
Steve Simon

 

Wavelet Pooling for Convolutional Neurual Networks

*Recommendation
2020
Data science
Travis Williams, Robert Li. Wavelet Pooling for Convolutional Neurual Networks. Published as a conference paper at ICLR 2018. Available in pdf format.
Aug 31, 2020
Steve Simon

 

Statisticians React to the News

*Recommendation
2020
Human side of statistics
International Statistical Institute. Statisticians React to the News. Available in html format.
Aug 28, 2020
Steve Simon

 

AI Fairness 360 Open Source Toolkit

*Recommendation
2020
Data science
IBM. AI Fairness 360 Open Source Toolkit. Available in html format.
Aug 21, 2020

 

Relationship Between Total and Bioaccessible Lead on Children’s Blood Lead Levels in Urban Residential Philadelphia Soils

*Recommendation
2020
Datasets
Teaching resources
Bradham KD, Nelson CM, Kelly J, et al. Relationship Between Total and Bioaccessible Lead on Children’s Blood Lead Levels in Urban Residential Philadelphia Soils. Environ Sci…
Aug 21, 2020

 

A New Standard For Publishing On Racial Health Inequities

*Recommendation
2020
Racial disparities
Rhea W. Boyd Edwin G. Lindo Lachelle D. Weeks Monica R. McLemore. On Racism: A New Standard For Publishing On Racial Health Inequities. Health Affairs 2020-07-02. doi…
Aug 21, 2020

 

Envisioning a Transformed Clinical Trials Enterprise in the United States

*Recommendation
2020
Clinical trials
nstitute of Medicine. 2012. Envisioning a Transformed Clinical Trials Enterprise in the United States: Establishing an Agenda for 2020: Workshop Summary. Washington, DC: The…
Aug 21, 2020

 

Setting the Stage: Statistical Collaboration Training Videos

*Recommendation
2020
Human side of statistics
Julia Sharp, Emily Griffith, and Megan Higgs, Ann Hess. Setting the Stage: Statistical Collaboration Training Videos. Available in html format.
Aug 20, 2020
Steve Simon

 

Upload data from R to an HTML page with rmarkdown and ftpUpload

*Recommendation
2020
R software
Linus Larsson. Upload data from R to an HTML page with rmarkdown and ftpUpload, Linus Larsson’s Blog - Data Science and Analytics, 2019-05-16. Available in html format.
Aug 16, 2020
Steve Simon

 

Filed under: The differences

*Recommendation
2020
Human side of statistics
Paul Dauenhauer. Tweet, 2020-08-14. Available in html format.
Aug 14, 2020
Steve Simon

 

Data 8: The Foundations of Data Science

*Recommendation
2020
Data science
University of California/Berkeley. Data 8: The Foundations of Data Science. Available in html format.
Aug 11, 2020
Steve Simon

 

Simple Demographics Often Identify People Uniquely

*Recommendation
2020
Data science
Ethics in research
Kaiyu Yang, Klint Qinami, Li Fei-Fei, Jia Deng, Olga Russakovsky. Towards Fairer Datasets: Filtering and Balancing the Distribution of the People Subtree in the ImageNet…
Aug 11, 2020
Steve Simon

 

Simple Demographics Often Identify People Uniquely

*Recommendation
2020
Ethics in research
Latanya Sweeney. Simple Demographics Often Identify People Uniquely. Carnegie Mellon University, Data Privacy Working Paper 3. Pittsburgh 2000. Available in pdf format
Aug 11, 2020
Steve Simon

 

Any sufficiently advanced math

*Quotation
2020
Data science
Some context is in order here. The quote is a take-off on Arthur C. Clarke’s famous quote: “Any sufficiently advanced technology is indistinguishable from magic.”…
Aug 11, 2020
Steve Simon

 

Health statistics represent

*Quotation
2020
Human side of statistics
An earlier version is here.
Aug 11, 2020
Steve Simon

 

Biography for a research grant

*Blog post
2020
Professional details
When you help write up a research grant, you need to brag about how smart and talented you are. I am not shy about promoting myself, so this is pretty easy for me to do.…
Aug 9, 2020
Steve Simon

 

The ASCCR Frame for Learning Essential Collaboration Skills

*Recommendation
2020
Professional details
Eric A. Vance, Heather S. Smith. The ASCCR Frame for Learning Essential Collaboration Skills. Journal of Statistics Education 2019-09-02. 27(3): 265-274. doi…
Aug 6, 2020
Steve Simon

 

How to be more effective in your professional life

*Recommendation
2020
Human side of statistics
Doug Zahn, How to be more effective in your professional life. Amstat News, 2009 09 01. Available in html format
Aug 6, 2020

 

Getting science published

*Recommendation
2020
Writing research papers
Kathryn Everson. Friends! Did you know that legitimate scientists publish their research in academic journals? Flickr 2020-05-13. Available in html format.
Jul 31, 2020

 

The Scientist’s Guide to Poster Design

*Recommendation
2020
Presenting research
Kathryn Everson. The Scientist’s Guide to Poster Design. Available in html format.
Jul 31, 2020

 

Data for Black Lives

*Recommendation
2020
Data science
Yeshimabeit Milner, Lucas Mason-Brown, Jamelle Watson-Daniels, Stacy Jebett Bullard, Nicole Triplett. Data for Black Lives. Available in html format.
Jul 30, 2020

 

AMS Style Guide

*Recommendation
2020
Writing research papers
Mary Letourneau, Jennifer Wright Sharp. AMS Style Guide. Journals. American Mathematical Society 2017. Available in pdf format.
Jul 15, 2020

 

Aleatory and epistemic uncertainties can completely derail medical research results

*Recommendation
2020
Critical appraisal
Incomplete page
Note: the name of this page needs to reflect the topic.
Jul 12, 2020

 

Attack on statistical significance: A balanced approach for medical research

*Recommendation
2020
Hypothesis testing
Abhaya Indrayan. Attack on statistical significance: A balanced approach for medical research. Indian Journal of Medical Research 2020. 151(4): 275-278. doi…
Jun 24, 2020
Steve Simon

 

The Human Experience Will Not Be Quantified

*Recommendation
2020
Human side of statistics
Phil Klay. The Human Experience Will Not Be Quantified. Why do we keep mistaking data for knowledge? The New York Times, 2020-11-07. Available in html format.
Jun 13, 2020

 

Florida fired its coronavirus data scientist. Now she’s publishing the statistics on her own.

*Recommendation
2020
Data mining
The COVID-19 crisis has caused a lot of contention over issues that normally would be ignored by everyone except a few specialists. As an example, Rebekah Jones was a data…
Jun 13, 2020
Steve Simon

 

Tests of trend between disease outcomes and ordinal covariates discretized from underlying continuous variables

*Recommendation
2020
Ordinal data
Brownstein, N.C., Cai, J. Tests of trend between disease outcomes and ordinal covariates discretized from underlying continuous variables: simulation studies and…
Jun 13, 2020

 

How to Call B.S. on Big Data.

*Blog post
2020
Data science
Michelle Nijhuis. How to Call B.S. on Big Data. A Practical Guide. The New Yorker. 2017-06-03. Approximately 1,300 words. Available in html format
Jun 11, 2020

 

Constructing sound science and good epidemiology: tobacco, lawyers, and public relations firms

*Recommendation
2020
Observational studies
Ong EK, Glantz SA. Constructing “sound science” and “good epidemiology”: tobacco, lawyers, and public relations firms. Am J Public Health. 2001;91(11):1749-1757.…
May 24, 2020

 

Steve Milloy misfires

*Recommendation
2020
Critical appraisal
Observational studies
Lambert T. Steve Milloy misfires. Science Blogs 2004-09-03. Available in html format.
May 24, 2020

 

In medicine, there is automatic

*Quotation
2020
Observational studies
In [medicine] there is automatic downgrading of observational studies below randomized (no matter how fine the former or irrelevant the latter - med RCTs are notorious for…
May 23, 2020
Steve Simon

 

The Bioconductor library of packages for R

*Blog post
2020
R software
Back in the previous decade, I spent a lot of time working on the various statistical methods required for genetics studies. It was difficult, but fun. For a variety of…
May 12, 2020
Steve Simon

 

The tendency of some modelers

*Quotation
2020
Critical appraisal
“The tendency of some modelers to present them as scientific predictions of the future rather than models does not help. Models are widely used in government, and some…
May 5, 2020
Steve Simon

 

Reading text files

*Blog post
2020
Data management
Rmarkdown code
Many data files stored on the Internet use text format. Here is an explanation of what text format is and how you can read it into a program for data analysis.
Apr 30, 2020
Steve Simon

 

An incomplete list of data repositories

*Blog post
2020
Teaching resources
This is a partial list of data repositories where you can store the datasets associated with your peer-reviewed publications. I am interested in assistance with this…
Apr 27, 2020
Steve Simon

Criticisms of the IHME COVID-19 model

*Blog post
2020
Epidemiology
Rmarkdown graphs
This blog post was created on 2020-04-23 and last modified on 2025-08-23.
Apr 23, 2020
Steve Simon

 

Codes for COVID-19 in the electronic health record

*Blog post
2020
Electronic health records
I might be helping with a research project that involves selection of medical records associated with COVID-19. Here are some of the resources and suggestions that I…
Apr 15, 2020
Steve Simon

 

Analyzing ordinal data with metric models: What could possibly go wrong?

*Recommendation
2020
Likert scales
Torrin M. Liddell and John K. Kruschke. Analyzing ordinal data with metric models: What could possibly go wrong? Journal of Experimental Social Psychology 2018. 79: 328 -…
Apr 13, 2020

Different map projections

Blog post
I have been drawing some maps in R and was struggling to figure out how to display things with the appropriate map projections. Here is some code where I experimented with a…
Mar 15, 2020
Steve Simon

An example of a poor color choice

*Blog post
2020
Graphical display
Rmarkdown graphs
I ran across a graph in a journal article. The article itself was good, but the graph had a rookie mistake. I shouldn’t point this out, because I myself have been guilty of…
Mar 11, 2020
Steve Simon

 

UMKC big data and data science initiatives

*Blog post
2020
Data science
I am trying to keep track of several recent initiatives at UMKC. Here are the details, as I best understand them.
Mar 10, 2020
Steve Simon

 

Food inspections

*Recommendation
2020
Datasets
City of Albuquerque. Food inspections. Available in html format.
Mar 4, 2020

 

Barbershop music

*Recommendation
2020
Datasets
Data Description. Barbershop Music. Available in text format.
Mar 4, 2020
Steve Simon

Smart quotes, em dashes, and en dashes

*Blog post
2020
Data management
Rmarkdown code
If you work with text data a lot, you will encounter some characters that are sort of close to what you need, but sort of not. These include the smart quotes, em dashes, and…
Mar 2, 2020
Steve Simon

 

Proposed talk on secondary data analysis

*Blog post
2020
Observational data
I am suggesting a talk on secondary data analysis for a seminar series here at UMKC. Here is the title and abstract.
Feb 27, 2020
Steve Simon

 

No aphorism is more frequently repeated

*Quotation
2020
Research design
“No aphorism is more frequently repeated in connection with field trials, than that we must ask Nature few questions, or, ideally, one question, at a time. The writer is…
Feb 21, 2020
Steve Simon

 

Data collection in a research methods class

*Blog post
2020
Teaching resources
One of the discussion boards sponsored by the American Statistical Association had a question about data collection exercises in a research methods class. The initial…
Feb 4, 2020
Steve Simon

 

Data visualizaiton as art

*Blog post
2020
Graphical display
I came across an interesting article in the New York Times and two books that all have a common theme. They use the tools of data visualization to make artistic statements.
Feb 4, 2020
Steve Simon

 

Printing R Markdown output to png files

*Blog post
2020
R software
I have been using a tedious process to convert parts of the output of an R Markdown file to png files. I want to use png files because they can be inserted easily into a…
Jan 29, 2020
Steve Simon

 

Artist wanted, here are the details

*Blog post
2020
Ethics in research
I have gotten several nibbles on a posting that I made last week. Here is some more information.
Jan 26, 2020
Steve Simon

 

Celebrating the failures of medical research using a graphic novel format

*Blog post
2020
Ethics in research
I sent out a flurry of small grants in December and most did not get funded, but one of them did. And I need your help with finding the right collaborator.
Jan 23, 2020
Steve Simon

 

Imbalanced sample sizes in the Fisher Exact test

*Blog post
2020
Measuring benefit and risk
Dear Professor Mean, We are conducting a study in which mice receive one of four different injections (various combinations of hormones and receptor antagonists)receive a…
Jan 17, 2020
Steve Simon

 

Identifying and manipulating non-breaking spaces

*Blog post
2020
Data management
Rmarkdown code
Non-breaking spaces are one of those weird little things in the computer that you have to keep your eye on. They can cause a lot of problems if they are assumed to be normal…
Jan 7, 2020
Steve Simon

 

Finding me on the Internet

*Blog post
2019
Professional details
It is worth tracking the limited number of websites that mention me (and not people who share my first and last name). Here are a few places where I get mentioned, albeit…
May 15, 2019
Steve Simon

 

PROC-X.com. An online (unofficial) SAS journal – written by bloggers

*Recommendation
2019
SAS software
A nice site that aggregates blog posts about SAS from a variety of authors.
May 10, 2019
Steve Simon

 

Scientists’ grant writing styles vary by gender

*Recommendation
2019
Grant writing
This is a brief summary of a research paper (apparently behind a pay wall, boo!) that looked at the language used in research grants submitted to the Gates Foundation. It…
May 9, 2019
Steve Simon

 

Assessment Resource Tools for Improving Statistical Thinking

*Recommendation
2019
Teaching resources
A great teaching resource with a test bank of items to assess knowledge and attitudes about Statistics. There are also links to other helpful resources.
May 2, 2019
Steve Simon

 

Several Python resources

*Blog post
2019
Python
I have not had the time to learn Python yet, but it is on my short term list of research goals. I attended a very nice talk about Python and data science and tried to get a…
May 2, 2019
Steve Simon

 

Data science curriculum roadmap

*Recommendation
2019
Data science
Teaching resources
How do you teach data science? That’s not an easy question because data science means different things to different people. This site shows different curricula depending on…
Apr 25, 2019
Steve Simon

 

A tribute to Douglas C. Altman, DSc

*Recommendation
2019
Important statisticians
This a brief and personal recollection of Doug Altman, a statistician who has had great influence in the practice of Statistics and the reporting of research results. There…
Apr 25, 2019
Steve Simon

 

Writing the methods section of a research paper

*Blog post
2019
Writing research papers
I’m teaching a class on Clinical Research Methodology and at least a few of the students are confused about what to put in the methods section of a research paper or a…
Apr 25, 2019
Steve Simon

 

Bibliographies and citations (in R Markdown)

*Recommendation
2019
Presenting research
R software
Writing research papers
If you want to use R Markdown to prepare research papers and presentations, you need to learn how to cite references and include a bibliography. This is a nice introduction…
Apr 18, 2019
Steve Simon

 

Separating Unique and Duplicated Observations Using PROC SORT in SAS 9.3 and Newer Versions

*Recommendation
2019
Data management
SAS software
SAS has some very powerful ways to find duplicate values and to store the duplicates separate from the unique values. Many of these use the sort procedure. Here is a nice…
Apr 18, 2019
Steve Simon

 

What would Florence Nightingale make of big data?

*Recommendation
2019
Data science
This is a nice video, professionally produced and very short (4 minutes) that shows the importance Florence Nightingale attached to Statistics. It reviews how she used…
Apr 17, 2019
Steve Simon

 

When Big Data goes to school

*Recommendation
2019
Data science
File this under the “dark side” of data science. Alfie Kohn is a critic of many of the motivational methods used in business and education, and he makes many good points in…
Apr 16, 2019
Steve Simon

 

Writing a discussion section: how to integrate substantive and statistical expertise

*Recommendation
2019
Writing research papers
The paper in BMC Medical Research Methodology gives practical step by step guidance on writing your discussion section.
Apr 16, 2019
Steve Simon

 

Copyright and Data

*Recommendation
2019
Data sharing
This is a nice one page document on copyright issues associated with research data and how to best share your research data with others.
Apr 7, 2019
Steve Simon

 

Case for omitting tied observations in the two-sample t-test and the Wilcoxon-Mann-Whitney Test

*Recommendation
2019
Nonparametric tests
When you are running a non-parametric test, like the Wilcoxon-Mann-Whitney test, you can only be 100% certain of the properties of that test (including Type I and Type II…
Apr 4, 2019
Steve Simon

 

When life gives you coloured cells, make categories

*Recommendation
2019
Data management
A lot of people use formatting to denote important information in an Excel spreadsheet. In particular, they will use the color of a cell to designate a particular category.…
Apr 3, 2019
Steve Simon

 

Ethical Practice in Data Mining

*Blog post
2019
Data science
This is a very nice summary of six major areas where data mining has led to serious ethical concerns.
Apr 1, 2019
Steve Simon

 

Writing the introduction section of a research thesis or dissertation

*Blog post
2019
Writing research papers
The introduction section of your research thesis or dissertation is the first thing that most people will read after reading the abstract. Some people use the introduction…
Mar 29, 2019
Steve Simon

 

Census Geocoder

*Recommendation
2019
Geocoding
This website will take an address, either on a form or as a batch of up to 10,000 addresses (CSV format) and provide latitude, longitude pairs as well as U.S. Census tract…
Mar 25, 2019
Steve Simon

 

Data Science Has Become About Lending False Credibility To Decisions We’ve Already Made

*Recommendation
2019
Data science
A rather harsh and cynical take on data science, but still worth reading. Let me share a story about this. Back in my college days (that would be the 1970s), someone found a…
Mar 25, 2019
Steve Simon

 

Harvard University Program on Survey Research

*Recommendation
2019
Survey design
This is a series of guides on survey research, written for the beginning student. It is written from the perspective of Political Science, but the advice works for other…
Mar 23, 2019
Steve Simon

 

A systematic review shows no performance benefit of machine learning over logistic regression for clinical prediction models

*Recommendation
2019
Data science
Logistic regression
Systematic overviews
This is one of those articles where you have to restrain yourself. Its message - that good old statistical tools like logistic regression can perform as well as these new…
Mar 15, 2019
Steve Simon

 

Webinar Series, Congressionally Directed Medical Research Programs

*Recommendation
2019
Grant writing
We live in a golden age of learning, where you find find just about anything you’d ever need to learn from on the Internet. One example of this is a series of webinars about…
Mar 14, 2019
Steve Simon

 

LaTeX/Mathematics

*Recommendation
2019
Presenting research
R software
Writing research papers
You can incorporate very nice looking mathematical formulas in R Markdown fairly easily. The system relies on LaTeX for displaying formulas and is surprisingly easy to…
Mar 8, 2019
Steve Simon

 

Did you hear about the mathematician

*Quotation
2019
Numbers
“Did you hear about the mathematician who was afraid of negative numbers? He would stop at nothing to avoid them.” (This joke is all over the Internet, and I’m not sure…
Mar 8, 2019
Steve Simon

 

R Markdown Basics

*Recommendation
2019
R software
Writing research papers
This is actually a nice “peek under the hood” approach with lots of practical advice about getting that last tweak in to make your results go from good to great.
Mar 8, 2019
Steve Simon

 

Stop Saying ‘Exponential.’ Sincerely, a Math Nerd.

*Recommendation
2019
Critical appraisal
This is a brief plea to avoid using the word “exponential” when you really mean “a lot.”
Mar 6, 2019
Steve Simon

 

12 things I wish I’d known before starting as a Data Scientist

*Recommendation
2019
Human side of statistics
This article was recommended to me at a webinar I attended. The author offers very personal and practical advice. The author’s third point “You’ll never have to know all the…
Mar 6, 2019
Steve Simon

 

Slapping the word pilot on a failed study

*Blog post
2019
Early stopping
Pilot studies
Someone was asking on the MedStats listserv about a study that had gone off the rails. They had recruited only about a third of the patients that they had wanted. Things…
Mar 3, 2019
Steve Simon

 

All scientific work is incomplete

*Quotation
2019
Critical appraisal
Observational studies
“All scientific work is incomplete - whether it be observational or experimental. All scientific work is liable to be upset or modified by advancing knowledge. That does not…
Feb 26, 2019
Steve Simon

 

Make a loud mistake

*Blog post
2019
Grant writing
Research design
Writing research papers
I dated a piano major in college and I tried - with very limited success, to learn how to play the piano myself. She told me - “If you’re going to make a mistake - make a…
Feb 15, 2019
Steve Simon

 

How to Use Deming’s 14 Points to Improve Quality

*Recommendation
2019
Quality improvement
This blog post provides a few short paragraphs elaborating on each of W. Edward Deming’s Fourteen Points. There’s a bit of self-promotion on this page, but the overall…
Feb 14, 2019
Steve Simon

 

Cartoon: Some good predictive analytics software

*Cartoon
2019
Data science
Purchased from CartoonStock.com for this blog site only. Do not reproduce this cartoon without their permission.
Feb 14, 2019
Steve Simon

 

A Framework for Program Evaluation

*Recommendation
2019
Quality improvement
This page offers a broad and comprehensive overview of how to plan and conduct a program evaluation. There are tons of resources (a mix of html pages and PDF documents)…
Feb 14, 2019
Steve Simon

 

Quality Improvement in Healthcare

*Recommendation
2019
Quality improvement
This is a slick video that outlines the quality improvement process using clever drawings. It is only 11 minutes long but provides a very nice overview.
Feb 14, 2019
Steve Simon

 

Checklist to Evaluate the Quality of Questions

*Recommendation
2019
Survey design
A detailed and comprehensive list of things to look for when you are reviewing a new questionnaire. It is based on a document QAS-99 that was originally developed by the…
Feb 14, 2019
Steve Simon

 

SMART Objectives

*Recommendation
2019
Quality improvement
The acronym SMART is a nice way to define an objective in a quality improvement. It has to be Specific, Measurable, Achievable, Relevant, and Time-Bound. This page outlines…
Feb 14, 2019
Steve Simon

 

8 Waste Types of DOWNTIME

*Recommendation
2019
Quality improvement
This page reviews the commonly used acronym DOWNTIME that classifies the eight ways that waste can occur in a manufacturing process.
Feb 14, 2019
Steve Simon

 

NOVA, A Hole in the Sky

*Recommendation
2019
Outliers
This 4 minute video talks about the discovery of the ozone hole over Antarctica and how some early indications of this hole were dismissed as outliers.
Feb 13, 2019
Steve Simon

 

Another short biography

*Blog post
2019
Professional details
I am contributing a chapter to a book (proposed title: Randomized controlled trials in medical research – gold standard or unhealthy fixation) and the book editor wanted a…
Feb 12, 2019
Steve Simon

 

Dr. Russell Waitman. Innovation: Breaking the Barriers on Medical Information

*Recommendation
2019
Professional details
This is a short article and video of Russ Waitman. Russ is my boss at one of my three jobs, and this gives a nice introduction to the sort of work I help out with.
Feb 12, 2019
Steve Simon

 

Finding those weird characters

*Blog post
2019
Statistical computing
When you take a text file from one system and use it in a different system, some of the more “exotic” characters can change on you. An example are the “smart quotes” in…
Feb 11, 2019
Steve Simon

 

Create Awesome HTML Table with knitr::kable and kableExtra

*Recommendation
2019
R software
I use R Markdown for a lot of things, but the one thing that never seems to come out the way I like is the tables. This vignette highlights some of the ways you can…
Feb 9, 2019
Steve Simon

 

An overview of randomization techniques

*Recommendation
2019
Randomization
This is a nice overview of why you want to randomize. It also talks about block randomization and covariate adaptive randomization.
Feb 5, 2019
Steve Simon

 

HEDIS and Performance Measurement

*Recommendation
2019
Quality improvement
This is another resource that came up during a talk. HEDIS is a series of performance measures in six clinical areas that is coordinated by the NCQA.
Feb 4, 2019
Steve Simon

 

The Learning Health Care System in America

*Recommendation
2019
Quality improvement
This document was recommended at a talk I attended. I have not read it yet, but the stated goal of the document to “drive the process of discovery as a natural outgrowth of…
Feb 4, 2019
Steve Simon

 

A Systematic Examination of the Citation of Prior Research

*Recommendation
2019
Writing research papers
This was a nice study, and shows a very easy model to adapt to other research problems. The authors were concerned that many reports of randomized clinical trials (RCTs)…
Feb 1, 2019
Steve Simon

 

The most challenging thing in the world

*Quotation
2019
Human side of statistics
“The most challenging thing in the world is not to learn fancy technologies, but control your own wild heart.” Yihui Xie, as quoted in Appendix C of Authoring Books wtih R…
Feb 1, 2019
Steve Simon

 

Bending the rules of clinical trials

*Recommendation
2019
Ethics in research
Many clinical trials have restrictive entry criteria to insure homogeneity of the subject pool which increases power and allows the study to proceed with a not too…
Jan 25, 2019
Steve Simon

 

Should you blow the whistle?

*Recommendation
2019
Fraud in research
This article offers some practical advice about when, how, and whether to become a whistle blower.
Jan 25, 2019
Steve Simon

 

Competing commitments in clinical trials

*Recommendation
2019
Ethics in research
The title is a bit misleading. It does not involve financial or non-financial conflicts of interest, but rather when clinical researchers violate the rules of a clinical…
Jan 25, 2019
Steve Simon

 

Observational studies often make clinical practice recommendations

*Recommendation
2019
Observational studies
This is a nice example of mining the existing medical literature to discover trends and attitudes about research. The authors take too dim a view, in my opinion, of what…
Jan 25, 2019
Steve Simon

 

Sample applications and more

*Recommendation
2019
Grant writing
It’s hard to find good examples of well-written research grants, so this website is wonderful. It shows examples of all sorts of NIH grants (R01, R03, R15, R21, R33, R41…
Jan 25, 2019
Steve Simon

 

Sins against science

*Recommendation
2019
Fraud in research
This article discusses some of the recent research showing the prevalence of scientific misconduct, offers some explanations on why this misconduct occurs, and provides some…
Jan 25, 2019
Steve Simon

 

Framingham Contribution to Cardiovascular Disease

*Recommendation
2019
Observational studies
The Framingham Heart Study, a massive longitudinal observational study, has helped identify most of the risk factors for heart disease that we commonly accept today. This…
Jan 23, 2019
Steve Simon

 

Think positively - what has research done for us

*Blog post
2019
Research design
Teaching resources
Several years ago, I was part of panel presentation at the Joint Statistical Meetings. My talk was on how to teach Statistics from an evidence-based perspective. A question…
Jan 23, 2019
Steve Simon

 

Quote: The combination of some data …

*Blog post
2019
Being updated
“The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from some data.” John Tukey, as quoted in The…
Jan 20, 2019
Steve Simon

 

Exploratory data analysis is an attitude

*Quotation
2019
Human side of statistics
Exploratory data analysis is an attitude, a state of flexibility, a willingness to look for those things that we believe are not there, as well as the things we believe…
Jan 20, 2019
Steve Simon

 

In a world where the price of calculation continues to decrease rapidly

*Quotation
2019
Data science
“In a world where the price of calculation continues to decrease rapidly, but the price of theorem proving continues to hold steady or increase, elementary economics…
Jan 20, 2019
Steve Simon

 

How to write a literature review

*Recommendation
2019
Writing research papers
This is a nice checklist of things that you should do when you are creating a literature review.
Jan 16, 2019
Steve Simon

 

Citing one of my web pages

*Blog post
2019
Writing research papers
I got an inquiry by email asking if it was okay to cite one of my web pages. Here’s what I said, more or less.
Jan 15, 2019
Steve Simon

 

Hints for designing effective questionnaires

*Blog post
2019
Survey design
I had originally cited this resources on my survey design category page, but the link was broken, so here is the correct link. It’s a nice guide. A bit too firm in its…
Jan 14, 2019
Steve Simon

 

Leading Questions – Yes Prime Minister

*Recommendation
2019
Survey design
This short video clip is an excellent illustration of how the questions leading up to a particular question on a survey can bias the response to that survey. It comes from a…
Jan 14, 2019
Steve Simon

 

How a Feel-Good AI Story Went Wrong in Flint

*Recommendation
2019
Data science
Ethics in research
Human side of statistics
Building a great statistical model does no one any good if it doesn’t pay attention to non-statistical issues. This story talks about a machine learning model to identify…
Jan 9, 2019
Steve Simon

 

Making women in science visible

*Recommendation
2019
Ethics in research
This video was recommended by my niece, and it caught my eye for a more subtle theme, perhaps. Rachel Ignotofsky is a great believer that illustration makes difficult…
Jan 9, 2019
Steve Simon

 

Congratulations on the Promotion. But Did Science Get a Demotion?

*Recommendation
2018
Ethics in research
I am recommending this article, not because I agree with it, but because it reinforces a common theme: the struggle to get and keep funding is skewing research as much as or…
Dec 31, 2018
Steve Simon

 

Convert PowerPoint Slides to xaringan (remark.js) Slides

*Recommendation
2018
Presenting research
R software
I have been constructing most of my recent presentations to R Markdown. This includes presentations that have little or no R code in them. I like using R Markdown because…
Dec 30, 2018
Steve Simon

 

9 Reasons Excel Users Should Consider Learning Programming

*Recommendation
2018
Data management
R software
Microsoft Excel is very popular, but it has many serious limitations. This article explains what you lose out on if you rely just on Excel and what additonal capabilities…
Dec 29, 2018
Steve Simon

 

We Have Ways To Stop Rogue Scientists. They Don’t Always Work.

*Recommendation
2018
Ethics in research
This is a nice review inspired by recent controversial work of a Chinese scientist who claims to have created genetically engineered babies. It outlines approaches that we…
Dec 29, 2018
Steve Simon

 

In UC’s battle with the world’s largest scientific publisher, the future of information is at stake

*Recommendation
2018
Writing research papers
The University of California (UC) is in the midst of a difficult negotiation with Reed Elsevier, a major publisher of research journals. The dispute relates to the…
Dec 11, 2018
Steve Simon

 

Standardized Mortality Ratio

*Recommendation
2018
Epidemiology
I was at a talk where mortality rates were presented in one column and the standardized mortality ratio was presented in a different column. I was a bit confused; I could…
Dec 11, 2018
Steve Simon

 

Make PowerPoint Presentations with R Markdown

*Recommendation
2018
Presenting research
R software
This is a 42 minute presentation that covers the basics of using R Markdown to produce PowerPoint files. It touches on another couple of RStudio products: R Studio Connect…
Dec 5, 2018
Steve Simon

 

Welcome to DASL – The Data And Story Library

*Recommendation
2018
Datasets
The Data and Story Library (DASL) is a collection of small and simple data sets useful for teaching basic statistical concepts. It was originally housed at the…
Nov 27, 2018
Steve Simon

 

Getting R to shut the heck up

*Blog post
2018
R software
When you are using R Markdown to create various documents, you are often interested in displaying any informative messages that appear along the way. This is especially true…
Nov 11, 2018
Steve Simon

 

Installing R and Python in Anaconda for Biologists

*Recommendation
2018
R software
Anaconda provides an easy way to manage the installation of both R and Python. The R installation includes R Studio, if you want it. While the title of this blog entry…
Nov 8, 2018
Steve Simon

 

Fighting SASism

*Blog post
2018
R software
SAS software
I told a story today in a webinar workshop that I thought I should get down in writing for my blog. It involves a prejudice unique among statisticians called SASism.
Oct 30, 2018
Steve Simon

 

Accessible R Markdown Documents

*Recommendation
2018
R software
Teaching resources
A class covering on-line teaching has reminded me about accessibility issues. This includes accessibility for blind students who rely on screen readers. This webpage post…
Oct 23, 2018
Steve Simon

 

Cleaning Words with R

*Recommendation
2018
Incomplete page
R software
Teaching resources
In many text mining or natural language processing applications, you will have problems with words that are very similar, but which are counted separately. An example might…
Oct 23, 2018
Steve Simon

 

1.1 Billion Taxi Rides with Spark 2.2 & 3 Raspberry Pi 3 Model Bs

*Recommendation
2018
Cluster computing
Mark Litwintschik has taken a large open source data set (1.1 billion taxi rides with data storage on the order of hundreds of gigabytes) and ran some benchmark queries on a…
Oct 23, 2018
Steve Simon

 

A top Cornell food researcher has had 13 studies retracted. That’s a lot.

*Recommendation
2018
Ethics in research
This is a non-technical account of Brian Wansink, a food researcher, who has been accused of p-hacking.
Sep 24, 2018
Steve Simon

 

Call R from SPSS

*Recommendation
2018
R software
SPSS software
This is a nice, easy to follow overview of how to use bits of R code within SPSS.
Sep 23, 2018
Steve Simon

 

What to do about claims of borderline statistical significance

*Blog post
2018
Hypothesis testing
A comment about the phrase “trend towards efficiency” on the Statistical Consulting Section discussion board raised a lot of interesting commentary. The phrase refers to a…
Sep 21, 2018
Steve Simon

 

What I did in the last twelve months

*Blog post
2018
Professional details
For the yearly evaluation for my part-time position in the Department of Biomedical and Health Informatics at the University of Missouri-Kansas City, I have had to prepare a…
Sep 19, 2018
Steve Simon

 

Making it easier to discover data sets

*Recommendation
2018
Data sharing
Datasets
I heard about this from the UMKC Bioinformatics twitter feed. Google has a blog entry highlighting a new search feature they’ve developed, Dataset Search. It lets you find…
Sep 14, 2018
Steve Simon

 

False-Positive Psychology

*Recommendation
2018
Hypothesis testing
This article was recommended at a talk I attended. The full title says it all.
Sep 14, 2018
Steve Simon

 

Complex Innovative Trial Designs Pilot Program

*Recommendation
2018
Research design
The FDA is encouraging new complex trial designs that are adaptive and/or Bayesian. This page describes a program where drug companies are encouraged to propose these…
Sep 13, 2018
Steve Simon

 

Use of Electronic Health Record Data in Clinical Investigations. Guidance for Industry

*Recommendation
2018
Electronic health records
The U.S. Food and Drug Administration (FDA) is encouraging great use of electronic health record data to supplement the traditional randomized clinical trials. But you need…
Sep 13, 2018
Steve Simon

 

Next-generation phenotyping of electronic health records

*Recommendation
2018
Electronic health records
This article was recommended at a talk I attended. The thesis is that we need to look at the electronic health record from the bottom up.
Sep 13, 2018
Steve Simon

 

Super Pi, a group to teach cluster computing using the Raspberry Pi

*Blog post
2018
Cluster computing
If you want to learn cluster computing and you didn’t have easy access, you had two choices. You could simulate a cluster computer on your laptop, or you could buy time in…
Sep 10, 2018
Steve Simon

 

The five safes, designing data access for research

*Recommendation
2018
Data sharing
This is a nice overview of the various dimensions of security that you need to consider when making research data available on the Internet.
Sep 7, 2018
Steve Simon

 

JupyterLab is Ready for Users

*Recommendation
2018
Integrated development environment
Jupyter is an integrated development environment that uses a notebook interface. It was originally developed for Python, but is now available for a variety of other…
Sep 7, 2018
Steve Simon

 

lavaan tutorial

*Recommendation
2018
Structural Equation Modeling
I have not run too many Structural Equation Modeling (SEM), so I can’t comment too much about this resource, but anytime I see something like SEM features added to R, I have…
Sep 7, 2018
Steve Simon

 

Leaflet - an open source Javascript library for mobile-friendly interactive maps

*Recommendation
2018
Geocoding
Graphical display
I have not tried this package but it was independently recommended by two separate sources that I have a lot of respect for. It uses a minimal computer interface to produce…
Sep 7, 2018
Steve Simon

 

Python bindings for MPI

*Blog post
2018
Cluster computing
The Python Software Foundation supports PyPA, the Python Packaging Authority, a group that maintains an easy to use infrastructure for distributing Python software packages.…
Sep 4, 2018
Steve Simon

 

Python, Raspberry Pi, and cluster computing

*Blog post
2018
Cluster computing
I’ve been experimenting with connecting a small number of Raspberry Pi in a cluster computer, and a good place to start is MPI (Message Passing Interface). Unfortunately…
Sep 4, 2018
Steve Simon

 

Cluster Hat 2.0

*Recommendation
2018
Cluster computing
I am working on creating a cluster computer using three Raspberry Pis. Once I get that working, I might see what I can do with the smaller model, the Raspberry Pi Zero. If I…
Sep 1, 2018
Steve Simon

 

MPI Tutorial Introduction

*Recommendation
2018
Cluster computing
MPI (Message Passing Interface) is the grandfather of all parallel programming systems. It is a series of routines that you can call from FORTRAN or C++ programs, and was…
Aug 31, 2018
Steve Simon

 

r2d3: R Interface to D3 Visualizations

*Recommendation
2018
Graphical display
R software
There’s an interesting visualization system called d3 that I only became aware of a few months ago. It uses a fairly minimal system, javascript and support vector graphics…
Aug 28, 2018
Steve Simon

 

What day is it in my R program?

*Blog post
2018
R software
There are three different ways to find out inside your R program what day it is. Let’s quickly look at each.
Aug 27, 2018
Steve Simon

 

Business essentials for starting an independent consulting practice

*Blog post
2018
Human side of statistics
Professional details
I’m giving a talk on Wednesday, August 22, titled “Business essentials for starting an independent consulting practice.” Here are a few details about this talk.
Aug 17, 2018
Steve Simon

 

How to Clone Your Raspberry Pi SD Cards With Windows

*Recommendation
2018
Raspberry Pi
I’m building a cluster of Raspberry Pi computers to run Hadoop and one of the tasks that I need is to make working backups of the micro SD cards that these computers use to…
Aug 15, 2018
Steve Simon

 

NOOBS – Raspberry Pi documentation

*Recommendation
2018
Raspberry Pi
You have several ways of installing the Raspbian operating system for the Raspberry Pi computers, but the simplest is to use NOOBS (New Out Of Box Software). This page shows…
Aug 15, 2018
Steve Simon

 

The Dark Side of Data Science

*Blog post
2018
Data science
Human side of statistics
I’m planning to give a talk on “The Dark Side of Data Science” and I’m hoping to get some interesting references and articles from my colleagues. Here is a first draft of my…
Aug 13, 2018
Steve Simon

 

Practical deep learning for coders

*Recommendation
2018
Data science
This is a MOOC (Massive Open Online Course) covering deep learning models. I have not taken it, but it comes highly recommended by others. It uses Python as the underlying…
Aug 1, 2018
Steve Simon

 

GloVe word vector embeddings

*Recommendation
2018
Data science
Text mining
When you are working with text mining, you might want to reduce the dimensionality of your problem. The word2vec algorithm, developed by Tomas Mikolov and others at Google…
Aug 1, 2018
Steve Simon

 

A simple structure for documentation

*Blog post
2018
Statistical computing
Teaching resources
Everybody has different standards for documentation, - and if you are already using a standard you like, don’t let me stop you. But if you’ve never used much documentation…
Jul 24, 2018
Steve Simon

 

Use of Electronic Health Record Data in Clinical Investigations

*Recommendation
2018
Data management
This press releases announces a “Guidance for Industry” document that the U.S. Food and Drug Administration provides from time to time on technical issues. This document…
Jul 23, 2018
Steve Simon

 

A Review of Published Analyses of Case-Cohort Studies and Recommendations for Future Reporting

*Recommendation
2018
Research design
I got a question about how to analyze a case cohort study in Stata. The person was following the code in a Stata conference presentation but was unsure about some of the…
Jul 20, 2018
Steve Simon

 

Grading rubric for computer assignments

*Blog post
2018
Statistical computing
Teaching resources
I’ve been teaching a variety of classes that require students to run a statistical analysis in a package like SAS or R and report the results. There is a tremendous variety…
Jul 20, 2018
Steve Simon

 

How to be more effective in your professional life

*Blog post
2018
Human side of statistics
This article starts with a nice anecdote about how you can be hurt by being dismissive about what someone else is saying. It also provides a nice structure, POWER, for…
Jul 10, 2018
Steve Simon

 

How much missingness can you tolerate?

*Blog post
2018
Missing data
I got a question about how much missing data could you have in a study and still feel comfortable with your data analysis. It’s a question with no hard and fast answer, but…
Jul 7, 2018
Steve Simon

 

Bayesian meta-analysis of two proportions in random control trials

*Recommendation
2018
Bayesian statistics
Systematic overviews
I got a question about Bayesian meta-analysis and found this nice teaching example. I’m not sure if the graphs are from the R package bayesmeta, but it looks like it.
Jul 5, 2018
Steve Simon

 

Section 508 CoP: PDF Accessibility – Part One

*Blog post
2018
Teaching resources
I have been somewhat lax in making my work accessible for people with disabilities. This video covers some of the basic things you can do with a PDF file to insure that it…
Jul 3, 2018
Steve Simon

 

Microsoft is creating an oracle for catching biased AI algorithms

*Recommendation
2018
Data science
Artificial Intelligence (AI) algorithms that are used for crime detection, loan approvals, and employee evaluations are considered by many to be objective, but they can…
Jun 28, 2018
Steve Simon

 

What goes into a contract for a consultation

*Blog post
2018
Human side of statistics
Someone asked me about what sort of contract to use with a new client. This person did not need a very detailed contract, but said that a handshake would not suffice. Here’s…
Jun 24, 2018
Steve Simon

 

Big data groups at UMKC and UM/Columbia

*Blog post
2018
Data science
I was at a meeting where I learned about some recent efforts with big data at the University of Missouri-Kansas City and the University of Missouri/Columbia. Here’s a brief…
Jun 9, 2018
Steve Simon

 

Applied Survival Analysis

*Recommendation
2018
Survival analysis
Although the title says “Applied”, this book has a fair amount of mathematics in it, which helps you understand why certain approaches work well. The sample outputs for this…
May 22, 2018
Steve Simon

 

Analysis of Pretest-Postest Designs

*Recommendation
2018
Longitudinal data
A very nice resource that talks about difference scores, relative change models, analysis of covariance, and repeated measures models.
May 22, 2018
Steve Simon

 

Interval censored data analysis

*Recommendation
2018
R software
Survival analysis
Michael Fay gave a short course on interval censored data at the 2010 useR! meeting. The slides from this short course provide a nice overview of the complexities of this…
May 21, 2018
Steve Simon

 

Interval regression - R data analysis examples

*Recommendation
2018
R software
Survival analysis
This page shows R code to handle the tricky data sets where the response is known to be inside some interval.
May 21, 2018
Steve Simon

 

Adjusted survival curves

*Recommendation
2018
R software
Survival analysis
This is a nice overview of how to use R to adjust survival curves in an observational study. It covers weighting and modeling with covariates and criticizes several…
May 20, 2018
Steve Simon

 

What are we doing to justify all that time we’re budgeting?

*Blog post
2018
Human side of statistics
An email discussion about the appropriate percentage effort on research grants has produced a lot of interesting discussions. One person raised an interesting question. The…
May 17, 2018
Steve Simon

 

beepr: easily play notification sounds on any platform

*Recommendation
2018
R software
This package was mentioned at the most recent meeting of the Kansas City R Users Group and was too cute not to mention.
May 13, 2018
Steve Simon

 

Some interesting quality improvement resources

*Blog post
2018
Quality improvement
I attended a conference on quality and patient safety, and some of the speakers mentioned some interesting resources. I googled them and saved the links here.
May 13, 2018
Steve Simon

 

Reproducible research with Stata

*Recommendation
2018
Reproducible research
Stata software
This outlines a way to produce “beautiful Beamer presentations” using Stata. This is a step towards the goal of reproducible research.
May 13, 2018
Steve Simon

 

Draft policy on statistical support for research

*Blog post
2018
Grant writing
I am drafting up a policy on statistical support for research at my part-time job at UMKC. It is loosely based on standards at the University of California, Davis and Kansas…
May 10, 2018
Steve Simon

 

Learning more about SAS

*Blog post
2018
SAS software
I had three students who successfully completed the Introduction to SAS class that I am teaching at UMKC. Here is the advice that I offered about how to continue to learn…
May 1, 2018
Steve Simon

 

Dogs vs cats. Create an algorithm to distinguish dogs from cats

*Recommendation
2018
Datasets
This is a classic data set for testing out image analysis. You have a data set of 25,000 images which are labelled dogs or cats. This is easy for a human to do, but can you…
Apr 19, 2018
Steve Simon

 

A crummy drop-down menu appeared to kill dozens of mothers in Texas.

*Recommendation
2018
Data management
This article talks about how bad the maternal mortality rates are in the United States and how bad our effort to try to quantify the rate is.
Apr 19, 2018
Steve Simon

 

SMS Spam Collection Data Set

*Recommendation
2018
Datasets
If you are interested in text mining, this is a good data set to start with. It is a bunch of text messages, each one line long, that have been classified by a human as…
Apr 19, 2018
Steve Simon

 

Definitions of Criteria and Considerations for Research Project Grant Critiques

*Blog post
2018
Grant writing
I have to help write NIH grants from time to time, and I need to always keep front and center the criteria that NIH peer reviewers use when they evaluate grants. They look…
Apr 11, 2018
Steve Simon

 

Exploits of a Mom

*Recommendation
2018
SQL
This xkcd cartoon by Scott Munro is open source, so I can hotlink the image directly. But if you go to the source, https://xkcd.com/327/, be sure to hover over the image for…
Apr 10, 2018
Steve Simon

 

Data Sharing Network (SHRINE)

*Recommendation
2018
Informatics
I’m ginvg a talk about i2b2 (among other things) and when browsing through their website, I cam across an interesting project, SHRINE. This is an acronym for Shared health…
Apr 10, 2018
Steve Simon

 

ISO 8601

*Recommendation
2018
Data management
This xkcd cartoon by Scott Munro is open source, so I can hotlink the image directly. But if you go to the source, https://xkcd.com/1179/, be sure to hover over the image…
Apr 9, 2018
Steve Simon

 

TinyTeX: A lightweight, cross-platform, portable, and easy-to-maintain LaTeX distribution based on TeX Live

*Recommendation
2018
R software
Reproducible research
Writing research papers
I’ve been using a version of LaTeX (MikTeX) for a couple of years, and it’s not bad. But when I heard about Yihui Xie’s R package, tinytex, I jumped at the opportunity to…
Apr 5, 2018
Steve Simon

 

Guidelines for estimating biostatistician effort and resources on grants

*Blog post
2018
Grant writing
What percentage effort is reasonable for Biostatistics support on a research grant? The UC Davis Biostatistics Group says 10% as a bare minimum, 35-60% for straightforward…
Apr 3, 2018
Steve Simon

 

Statistical and Machine Learning forecasting methods: Concerns and ways forward

*Blog post
2018
Data science
At first glance, you might think that this article looks like a vindication of traditional statistics. Classical time series models (methods that were available in the…
Apr 3, 2018
Steve Simon

 

The Reinhart-Rogoff error – or how not to Excel at economics

*Recommendation
2018
Data management
There has been a lot written about how lousy Microsoft Excel (and other spreadsheet products) are at data management, but the warning sinks in so much more effectively when…
Apr 3, 2018
Steve Simon

 

EuSpRIG horror stories.

*Recommendation
2018
Data management
There has been a lot written about data management problems with using spreadsheets, and there is a group the European Spreadsheet Risks Interest Group that has documented…
Apr 3, 2018
Steve Simon

 

Developing an interdisciplinary research program

*Blog post
2018
Professional details
I’ve been applying for a variety of jobs, and one of them asked for a statement on how I would develop an interdisciplinary research program. It’s fun to write these, and I…
Apr 2, 2018
Steve Simon

 

My research interests

*Blog post
2018
Professional details
I’ve been applying for a variety of jobs, and one of them asked for a statement on my research interests. I tried to emphasize the collaborative nature of my research.…
Apr 2, 2018
Steve Simon

 

My research interests, one page limit

*Blog post
2018
Professional details
Another place asked for my research interests and asked me to keep it to a single page. Gack! I do not have an easy time keeping withing page limits. Here’s what I wrote. It…
Apr 2, 2018
Steve Simon

 

My teaching interests, one page limit

*Blog post
2018
Professional details
I have been applying to a variety of jobs, and some of them, mostly universities, want a statement of teaching philosophy, research interests, or some combination. I enjoy…
Apr 2, 2018
Steve Simon

 

My teaching approach

*Blog post
2018
Professional details
I am applying for a variety of jobs and some of the universities that I am applying to want to know my approach to teaching. It’s an interesting thing to write about…
Apr 2, 2018
Steve Simon

 

Pmean: My teaching and research statement

*Blog post
2018
Professional details
I am applying to a variety of jobs and some of them ask for a statement about teaching or research. Here’s something I wrote where the employer asked for a combination of…
Apr 2, 2018
Steve Simon

 

To combat physician burnout and improve care, fix the electronic health record

*Blog post
2018
Informatics
This article is a nice counterbalance to all the glowing reports about how moving to the electronic health record is going to revolutionize health care. This effort…
Apr 1, 2018
Steve Simon

 

Evaluation Methods in Biomedical Informatics

*Recommendation
2018
Informatics
When I was talking about using the electronic health record as a measurement tool for quality improvement studies, a colleague recommended that I look at a book, Evaluation…
Mar 29, 2018
Steve Simon

 

Starting a heron-i2b2-analytics repository

*Blog post
2018
Informatics
I am working on a CTSA grant to develop repeatable downstream pipelines that directly access i2b2 and CDM. In order to promote this work and encourage others to participate…
Mar 29, 2018
Steve Simon

 

Recommended format for homework assignments

*Blog post
2018
R software
SAS software
SPSS software
I’m teaching a couple of classes, Introduction to R and Introduction to SAS, and I’m finding that students will turn in homework a variety of different ways. I’m fine with…
Mar 28, 2018
Steve Simon

 

And the least important variable is

*Blog post
2018
Human side of statistics
Linear regression
I heard a story a long time ago, and I don’t remember who told it to me and I’m probably getting all the details wrong, but I wanted to try to recreate the story from memory…
Mar 28, 2018
Steve Simon

 

Using the transpose procedure in SAS

*Blog post
2018
SAS software
A couple of my students are having difficulty with restructuring data sets in SAS. This is not surprising. Restructuring is very important, but not so easy. I decided to run…
Mar 28, 2018
Steve Simon

 

Good Publication Practice for Communicating Company-Sponsored Medical Research: GPP3

*Recommendation
2018
Writing research papers
Very little of my research fits into the category of company-sponsored medical research, but it is important to be aware of the special concerns and the extra oversight that…
Mar 27, 2018
Steve Simon

 

Next stop - BMC Medical Informatics and Decision Making

*Blog post
2018
Informatics
Professional details
I’m working part-time on a research grant and I want to publish some of the work I’ve done on this grant. The title of the paper tentatively is “Validating elastic net…
Mar 27, 2018
Steve Simon

 

Two articles published in the Encyclopedia of Big Data

*Blog post
2018
Data science
Professional details
I don’t call myself a “big data” analyst, but when a call went out seeking authors for various topics for the Encyclopedia of Big Data, I volunteered to write two articles.…
Mar 25, 2018
Steve Simon

 

Textbook Examples Applied Survival Analysis

*Recommendation
2018
R software
SAS software
SPSS software
Stata software
Survival analysis
Teaching resources
I’m teaching an online workshop for The Analysis Factor on survival analysis. It’s not announced yet, and I have a LOT of work to do before it is ready. One thing that will…
Mar 24, 2018
Steve Simon

 

They want a short biography from me

*Blog post
2018
Professional details
I should have titled this page “I’m a Star!” because the School of Medicine’s Marketing and Communications Office is asking me questions to prepare a short biography to…
Mar 23, 2018
Steve Simon

 

Welcome to developerWorks

*Recommendation
2018
Data science
Teaching resources
I got this recommendation from a friend. IBM has a large number of free resources explaining things like cloud computing and blockchain. I’m most interested in their section…
Mar 23, 2018
Steve Simon

 

Tests of equivalence and non-inferiority

*Blog post
2018
Hypothesis testing
I’m making a webinar presentation in April for The Analysis Factor. I’ve done this several times in the past. The talk in April will be on tests of equivalence and…
Mar 23, 2018
Steve Simon

 

Exporting a graph in SAS

*Blog post
2018
SAS software
I got a question about how to export a graph in SAS to a program like PowerPoint. There are several ways to do this, and I explained that you can right click on any graph…
Mar 23, 2018
Steve Simon

 

Getting Started with the SAS 9.4 Output Delivery System

*Recommendation
2018
SAS software
I don’t use SAS that much anymore. Not because it’s a bad program. Mostly it’s because it’s hard to keep on top of too many statistical packages all at once. But I’m…
Mar 23, 2018
Steve Simon

 

Mining the electronic health record, why and how

*Blog post
2018
Informatics
I’m submitting a talk to an upcoming research conference. I’m not sure if they’ll accept it, but wish me luck. Here’s the title and abstract.
Mar 22, 2018
Steve Simon

 

Peer grading in Introduction to R, SPSS, SAS

*Blog post
2018
R software
SAS software
SPSS software
I’ve gotten some helpful feedback that I need to encourage more interactions among students in the on-line classes, Introduction to R, Introduction to SPSS, and Introduction…
Mar 22, 2018
Steve Simon

 

Changes to the Introduction to R, SAS, and SPSS classes

*Blog post
2018
R software
SAS software
SPSS software
I have helped develop and have taught (along with other faculty in our department) three one credit hour pass/fail classes: Introduction to R, Introduction to SPSS, and…
Mar 21, 2018
Steve Simon

 

Is vaccine effectiveness (VE) different from vaccine efficacy

*Recommendation
2018
Critical appraisal
This is a non-technical discussion of the difference between effectiveness and efficacy (two easily confused terms) in the context of vaccination. Short answer: efficacy is…
Mar 1, 2018
Steve Simon

 

A sampling of outstanding women in analytics

*Recommendation
2018
Important statisticians
This is a list (with single paragraph descriptions) of 186 women who have accomplished great things in the area of Analytics. There is a brief accompanying article at the…
Feb 28, 2018
Steve Simon

 

Mixed up variable names in SAS

*Blog post
2018
SAS software
Some of my students in the Introduction to SAS class were having trouble reading in a tab-delimited text file, and it’s not too surprising, because some of the student in…
Feb 26, 2018
Steve Simon

 

Data dictionaries

*Recommendation
2018
Data management
This is a nice explanation of what goes into a data dictionary, written from the perspective of research data management.
Feb 24, 2018
Steve Simon

 

The history of Hadoop

*Recommendation
2018
Statistical computing
If you want to understand big data, you need to understand Hadoop. Hadoop is the technology underlying many big data efforts. But most of the descriptions of Hadoop are…
Feb 24, 2018
Steve Simon

 

Adherence to Methodological Standards in Research Using the National Inpatient Sample

*Recommendation
2018
Datasets
I normally don’t recommend articles that are stuck behind pay walls, but this is an important article. It shows how 85% of a sample of research studies using the National…
Feb 20, 2018
Steve Simon

 

Cleaning Words with R: Stemming, Lemmatization & Replacing with More Common Synonym

*Recommendation
2018
R software
Text mining
In many text mining or natural language processing applications, you will have problems with words that are very similar, but which are counted separately. An example might…
Feb 20, 2018
Steve Simon

 

Sentiment analysis of A Christmas Carol

*Blog post
2018
Text mining
I was at an interesting talk about sentiment analysis and decided to try something simple myself. Sentiment analysis is a text analytics method that compares text data with…
Feb 13, 2018
Steve Simon

 

Reading text data into SAS

*Blog post
2018
SAS software
Some of my students in my Introduction to SAS class are having trouble with a particular data set. Here are some screen shots showing how SAS can read this file in several…
Feb 9, 2018
Steve Simon

 

Quote: Without data

*Quotation
2018
Quality improvement
“Without data, you’re just another person with an opinion.” W. Edwards Deming. As quoted at https://www.goodreads.com/author/quotes/310261.W_Edwards_Deming.
Feb 9, 2018
Steve Simon

 

An introduction to implementation science for the non-specialist

*Recommendation
2018
Critical appraisal
I’ve done a lot of work with Evidence-Based Health, but one big and largely unsolved problem is how to get health care professionals to change their practices once the…
Feb 6, 2018
Steve Simon

 

Do you need to name your function arguments in R?

*Blog post
2018
R software
If you program anything in R, you’ll end up calling a lot of functions. You pass your data or your constants to these functions, and you can do it in one of two ways. You…
Feb 4, 2018
Steve Simon

 

The Survey Statistician newsletter

*Recommendation
2018
Survey design
The International Association of Survey Statisticians publishes a newsletter every six months that covers general information about surveys, announcements about meetings…
Jan 30, 2018
Steve Simon

 

Possible webinars on consulting

*Blog post
2018
Human side of statistics
Professional details
I’ve gotten an inquiry about teaching a couple of webinars. Nothing’s official yet, but let me outline the? these webinars here on my blog. If the offer becomes official, I…
Jan 29, 2018
Steve Simon

 

My work on a CTSA grant

*Blog post
2018
Data science
R software
SQL
I’m on a Clincal and Translational Science Award (CTSA) research grant (5UL1TR000001-05, formerly 1U54RR031295-01A1), which is pretty cool. My name is even mentioned a few…
Jan 26, 2018
Steve Simon

 

Hi - I’m Mike Bostock.

*Recommendation
2018
Graphical display
Important statisticians
This is an AMA (Ask Me Anything) session with Mike Bostock, a former graphics editor for the New York Times and creator of the d3.js data visualization package. I’ll be…
Jan 23, 2018
Steve Simon

 

How to be more effective in your professional life

*Recommendation
2018
Human side of statistics
This post has been combined with a similar post written on 2020-08-06.
Jan 22, 2018
Steve Simon

 

Charging by the hour versus charging by the project

*Blog post
2018
Human side of statistics
I was talking about pricing models for consulting in an email exchange and I thought I’d extract some of those comments for this blog. When you are an independent…
Jan 17, 2018
Steve Simon

 

Syllabus for Introduction to R, Spring 2018

*Blog post
2018
R software
I am teaching a class, Introduction to R (MEDB 5505). Here is the syllabus for Spring Semester 2018.
Jan 14, 2018
Steve Simon

 

Syllabus, Introduction to SAS, Spring 2018

*Blog post
2018
SAS software
I am teaching a class, Introduction to SAS (MEDB 5507). Here is the syllabus for Spring Semester 2018.
Jan 14, 2018
Steve Simon

 

SAS University. It’s SAS and it’s free

*Blog post
2018
SAS software
I am teaching a class, Introduction to SAS, that I helped design, but one where another faculty member did all the heavy lifting. I used to teach SAS classes, and I even…
Jan 12, 2018
Steve Simon

 

The Origins of ‘Big Data’

*Recommendation
2018
Data science
I’m not a big fan of the term “big data” but I’ve been applying for a couple of jobs that ask for expertise in big data instead of expertise in Statistics. So in one of the…
Jan 2, 2018
Steve Simon

 

Philosophy News Network: Postmodernism Special Report

*Recommendation
2018
Critical appraisal
I generally shy away from Philosophical debates, but I did discuss a Postmodern critique of Evidence Based Medicine a while back. When one of my more intellectual friends…
Jan 2, 2018
Steve Simon

 

Recommendation: Philosophy News Network: Postmodernism Special Report

*Recommendation
2018
Critical appraisal
I generally shy away from Philosophical debates, but I did discuss a Postmodern critique of Evidence Based Medicine a while back. When one of my more intellectual friends…
Jan 2, 2018
Steve Simon

 

Another big data publication

*Blog post
2017
Professional details
I dislike the term “big data” because it implies a class of problems that are immune from normal statistical considerations. I will admit that certain concepts such as the…
Dec 29, 2017
Steve Simon

 

My research interests in 450 characters or less.

*Blog post
2017
Professional details
I am currently looking for a full-time position. I have been part-time since 2008, because of child care issues. That will change in July 2018 when my wife retires. She’s…
Dec 28, 2017
Steve Simon

 

My grade point averages

*Blog post
2017
Professional details
In applying for various jobs, one of them wanted to know my grade point averages from school. That was over 35 years ago, but okay. I had to calculate them by hand and I…
Dec 28, 2017
Steve Simon

 

Designing and conducting semi-structured interviews for research

*Recommendation
2017
Qualitative research
This is a very helpful guide on collecting qualitative data through a semi-structured interview. It emphasizes the need for probe questions and on behaviors that you should…
Dec 27, 2017
Steve Simon

 

No more rainbows

*Blog post
2017
Graphical display
This is a nice article explaining why using a rainbow (red-orange-yellow-green-blue-indigo-violet) is a bad idea. The colors produce an artefactual banding pattern, they do…
Dec 15, 2017
Steve Simon

 

Network analysis in cross-sectional data using R

*Recommendation
2017
Network analysis
These are the slides for a very nice webinar presented by Eiko Fried. Dr. Fried provided a wealth of resources during his webinar (some of these are behind pay walls).
Dec 12, 2017
Steve Simon

 

How to use social media in your career

*Recommendation
2017
Human side of statistics
This is a short overview of five major social media sites: LinkedIn, Twitter, Facebook, Instagram, and Snapchat and how you might use them to promote your career. The…
Dec 4, 2017
Steve Simon

 

January talk at KU

*Blog post
2017
Professional details
Networking is important, and until recently I have failed to build bridges with some of the very smart people working at the University of Kansas in Lawrence. But I will be…
Nov 28, 2017
Steve Simon

 

Can A.I. be taught to explain itself

*Recommendation
2017
Data science
This is a nice article in the popular press that talks about some of the problems with “black box” models (in particular deep neural nets) used extensively in many big data…
Nov 27, 2017
Steve Simon

 

Losing track of your transformed variables in R

*Blog post
2017
R software
I got an interesting question from one of my students, and it illustrates a subtle issue that may confuse beginning R programmers. The student was trying to compute a ratio…
Nov 22, 2017
Steve Simon

 

Resources for R

*Blog post
2017
R software
Teaching resources
I attended several talks about R at the Joint Statistics meetings and noted some interesting packages and other resources during these talks. I lost track of that list until…
Nov 22, 2017
Steve Simon

 

Beanumber repository

*Recommendation
2017
Data science
R software
SQL
Teaching resources
This is the github repository of Ben Baumer. He is one of the co-authors of “Modern Data Science with R” and the data and code from that book is available here. He also…
Nov 15, 2017
Steve Simon

 

Databases using R

*Recommendation
2017
R software
SQL
This is a page outlining several related efforts at RStudio to make it easier for you to work with data stored in various relational databases.
Nov 15, 2017
Steve Simon

 

Teaching precursors to data science in introductory and second courses in statistics

*Recommendation
2017
Data science
Teaching resources
This paper talks about how to get students to think about large databases in an introductory class that normally uses “toy” problems with a few dozen rows of data.
Nov 15, 2017
Steve Simon

 

Intro to SQL for Data Science

*Recommendation
2017
SQL
Teaching resources
This is a series of videos and homework exercises that you can work on at your own pace. I have only viewed the outline for this, but anything from DataCamp comes highly…
Nov 15, 2017
Steve Simon

 

Writing about numbers

*Blog post
2017
Numbers
This is a chapter in a classic book, Medical Uses of Statistics. The writer of this particular chapter was a giant in Statistics, Frederick Mosteller. This chapter talks…
Nov 8, 2017
Steve Simon

 

When the revolution came for Amy Cuddy

*Recommendation
2017
Critical appraisal
Human side of statistics
This is one of the best articles I have ever read in the popular press about the complexities of the research process.
Oct 19, 2017
Steve Simon

 

The unthinking approach to borderline p-values

*Blog post
2017
Hypothesis testing
Writing research papers
I ran across a nice discussion of how to write the results section of a research paper, but it has one comment about the phrase “trend towards significance” that I had to…
Oct 19, 2017
Steve Simon

 

Get credit for your data – BMC Research Notes launches data notes

*Recommendation
2017
Datasets
Writing research papers
This is a new effort to get data out into the open for others to use. A data note can be on data that was not published or it could be an addendum describing data used in…
Oct 17, 2017
Steve Simon

 

100 interview questions? A big oops on the very first one.

*Blog post
2017
Statistical theory
I shouldn’t do this, because we’ve all made mistakes, especially me. But I took a peek at a website with the intriguing title “100+ commonly asked data science interview…
Oct 17, 2017
Steve Simon

 

Search for unpublished data by systematic reviewers: an audit

*Recommendation
2017
Publication bias
The authors looked at all systematic reviews (excluding methodological reviews) published in a few key journals as well as a random sample of Cochrane reviews to see how…
Oct 17, 2017
Steve Simon

 

What does large mean when talking about negative values?

*Blog post
2017
Diagnostic testing
Human side of statistics
Dear Professor Mean, I saw a paper where the authors said that they wanted a diagnostic test with a large negative likelihood ratio, because it was important to rule out a…
Oct 13, 2017
Steve Simon

 

OpenRefine: A free, open source, powerful tool for working with messy data

*Recommendation
2017
Data management
I have not had a chance to use this, but it comes highly recommended. OpenRefine is a program that uses a graphical user interface to clean up messy data, but it saves all…
Sep 28, 2017
Steve Simon

 

How to increase value and reduce waste when research priorities are set

*Recommendation
2017
Research design
This is the first in a series of articles on reducing waste in research. It focuses on funding agencies and recommends that funders should support more work on making…
Sep 25, 2017
Steve Simon

 

Randomized Controlled Trials in Health Insurance Systems

*Recommendation
2017
Randomization
Research design
While researchers often use data from health insurance systems to conduct observational studies, the authors of this research paper point out that you can also conduct…
Sep 20, 2017
Steve Simon

 

Announcing a new monthly feature: What’s going on in this graph

*Recommendation
2017
Graphical display
Teaching resources
Through the effort of a team of statisticians with the American Statistical Association, the New York Times is producing a new resource for educators called “What’s Going On…
Sep 14, 2017
Steve Simon

 

Notice of Revised NIH Definition of Clinical Trial

*Recommendation
2017
Research design
The NIH recently updated their definition of what a clinical trial is. Here is the link to the new definition. Also worth reviewing are an FAQ list, some case studies, some…
Sep 13, 2017
Steve Simon

 

Trump’s Android and iPhone tweets - one year later

*Recommendation
2017
R software
Text mining
This is a nice example of using R for text mining of twitter feeds - and the author gives lots of links and hints on how you could do something similar.
Sep 13, 2017
Steve Simon

 

Good enough practices in scientific computing

*Recommendation
2017
Data management
Writing research papers
There is more than one way to approach a data analysis and some of the ways lead to easier modifications and updates and help make your work more reproducible. This paper…
Sep 5, 2017
Steve Simon

 

Syllabus for Introduction to R, Fall semester 2017

*Blog post
2017
R software
I am teaching a class, Introduction to R (MEDB 5505). Here is the syllabus for Fall Semester 2017.
Aug 31, 2017
Steve Simon

 

Open source as a budgetary measure

*Blog post
2017
R software
Writing research papers
Like a lot of public universities, UMKC is having a lot of financial difficulty. They are asking for advice from faculty members on how to address this budget shortfall. Not…
Aug 30, 2017
Steve Simon

 

Syllabus for Introduction to SPSS, Fall semester 2017

*Blog post
2017
SPSS software
I am teaching a class, Introduction to SPSS (MEDB 5506). Here is the syllabus for Fall Semester 2017.
Aug 30, 2017
Steve Simon

 

A quick summary of my research

*Blog post
2017
Professional details
I might be giving a very brief (5 minute) overview of my research for students in the Department of Biomedical and Health Informatics. Here are some details of that work…
Aug 28, 2017
Steve Simon

 

Dryad Digital Repository

*Recommendation
2017
Data sharing
Datasets
I’ve been looking for something like this for a while. It is a repository for data sets associated with peer-reveiwed publicattions. I have only glanced at it briefly, but…
Aug 16, 2017
Steve Simon

 

Conferences for learning R

*Blog post
2017
R software
I heard about a new series of conferences for learning about R. I have not attended any of them, but they look interesting.
Aug 13, 2017
Steve Simon

 

What are the important packages for R

*Blog post
2017
R software
I got a question from one of the students in my “Introduction to R” class asking what are the important packages for R. That’s a hard question to answer, but if I got only…
Jul 27, 2017
Steve Simon

 

Greece’s troubling prosecution of its former chief statistician

*Recommendation
2017
Human side of statistics
This is an important summary about the prosecution of a statistician, Andreas Georgiu, who was only doing his job.
Jul 12, 2017
Steve Simon

 

Analyze Survey Data for Free

*Recommendation
2017
Complex surveys
R software
I’ve not had a chance to test this code, but it looks pretty good for anyone who might want to analyze one of the dozens of large databases produced by the U.S. Government.
Jul 12, 2017
Steve Simon

 

Is the staggeringly profitable business of scientific publishing bad for science?

*Recommendation
2017
Writing research papers
I attended a talk about a decade ago on the problems with for-profit publishing of scientific research and the need to aggressively adopt the open source publication model.…
Jul 10, 2017
Steve Simon

 

The new Enigma Public

*Recommendation
2017
Datasets
This is yet another interesting source of data. This site specializes in databases prepared by the United States government.
Jun 26, 2017
Steve Simon

 

Kaggle data

*Recommendation
2017
Datasets
In contrast to the five thirty eight databases which are mostly smallish, the Kaggle data sets are, as a rule, very large. They also include a lot of text data, for natural…
Jun 19, 2017
Steve Simon

 

Five Thirty Eight Data

*Recommendation
2017
Datasets
This is a github repository of a lot of interesting data sets created by the Five Thirty Eight website. I presume there is a story associated with most of these data sets.…
Jun 16, 2017
Steve Simon

 

ProbOnto

*Recommendation
2017
Probability concepts
If you work with probability distributions a lot, you find there are multiple parameterizations (e.g., the two different forms of the exponential distribution), as well as…
Jun 12, 2017
Steve Simon

 

It only looks like a blank

*Blog post
2017
R software
I was having trouble with trailing blanks in an R program. There were some strings that looked like ” Y” and “Y” and it’s easy enough to fix this, but one of the “Y” values…
May 24, 2017
Steve Simon

 

This is your machine learning system?

*Recommendation
2017
Data science
This xkcd cartoon by Scott Munro is open source, so I can hotlink the image directly. But if you go to the source, https://xkcd.com/1838/, be sure to hover over the image…
May 18, 2017
Steve Simon

 

Why R is Bad for You

*Recommendation
2017
R software
Arguing about R versus SAS often takes on a religious fervor, so I normally hesitate to recommend articles that trash one package or the other. But this one raises an…
May 18, 2017
Steve Simon

 

A p-value of .000

*Blog post
2017
Ask Professor Mean
Hypothesis testing
I ran a statistical test in SPSS and got a p-value of .000. I re-ran the same data in Microsoft Excel and got a p-value of 3.9433E-9. I know from scientific notation that…
May 8, 2017
Steve Simon

 

Extremely imbalanced multi-center trials

*Blog post
2017
Accrual problems
Bayesian statistics
There was some recent discussion of issues with multi-center trials where one center dominates, contributing as much as 94% of all the patients. What does this do to the…
May 5, 2017
Steve Simon

 

One in Five Clinical Trials for Adults with Cancer Never Finish

*Recommendation
2017
Accrual problems
This is a research summary of a study that found one out of every five cancer trials that “did not finish” which actually means that they stopped early for futility, if I am…
May 5, 2017
Steve Simon

 

Getting out of the free consulting trap

*Blog post
2017
Human side of statistics
Someone on the Statistical Consulting Section message board asked a question about how to handle a situation where a colleague was repeatedly asking for advice. How do you…
May 4, 2017
Steve Simon

 

The numbers for the Science March

*Recommendation
2017
Humor
Placebos in research
I normally don’t recommend other people’s tweets, but these two from Siobhan Tompson were too funny to pass up.
May 4, 2017
Steve Simon

 

ROSE: A package for binary imbalanced learning

*Recommendation
2017
Data science
Logistic regression
Logistic regression and other statistical methods for predicting a binary outcome run into problems when the outcome being tested is very rare, even in data sets big enough…
May 2, 2017
Steve Simon

 

How big is the stuff I’m working on

*Blog post
2017
Professional details
I have been working part-time on a project for the Great Plains Collaborative (GPC) under the direction of Russ Waitman and the gentle guidance of Dan Connolly, both at…
May 2, 2017
Steve Simon

 

Proving the null hypothesis in clinical trials

*Recommendation
2017
Hypothesis testing
I’m attending a great short course on non-inferiority trials and the speaker provided a key reference of historical interest. This reference is the one that got the…
Apr 27, 2017
Steve Simon

 

How Bright Promise in Cancer Testing Fell Apart

*Recommendation
2017
Data science
A nice overview of the problems with shoddy research in genetics testing. It highlights the work of “forensic statistics” of Keith Baggerly and Kevin Coombes.
Apr 13, 2017
Steve Simon

 

Genetics: Clues in the code

*Recommendation
2017
Data science
If you want to understand the value of genomic medicine, you can learn a lot by reviewing the case of Nicholas Volker, one of the first success stories in this area. Here’s…
Apr 13, 2017
Steve Simon

 

Standards and guidelines for the interpretation of sequence variants

*Recommendation
2017
Data science
This article outlines a standardized way to describe genetic variants.
Apr 13, 2017
Steve Simon

 

Blind analysis: Hide results to seek the truth

*Recommendation
2017
Blinding in research
This paper advocates something I would call a triple blind, keeping the doctor, the patient, and the statistician who analyzes the data in the dark as to which treatment…
Apr 11, 2017
Steve Simon

 

Launch a Shiny App on Your Own Server in 4 Steps

*Recommendation
2017
R software
It’s very easy, apparently, to set up your own server to run Shiny apps (Shiny is a web based method for interacting with R code). If you have set up Amazon Web Services…
Apr 10, 2017
Steve Simon

 

Obnoxious use of red text in RStudio

*Blog post
2017
R software
I really enjoy using RStudio, but one thing about it drives me bats. It seems to use red text for some very innocuous error messages.
Apr 7, 2017
Steve Simon

 

Why be an independent consultant?

*Recommendation
2017
Human side of statistics
Professional details
I might as well recommend something that I wrote. This is a short article in the Amstat News, a monthly newsletter of the American Statistical Association. I talk about all…
Apr 4, 2017
Steve Simon

 

My areas of expertise

*Blog post
2017
Professional details
I was asked to list my areas of expertise for an upcoming Q&A webinar that I am helping with. Here’s the list I shared.
Mar 30, 2017
Steve Simon

 

Will the baby walk away?

*Blog post
2017
Probability concepts
I submitted a cute probability problem to the Riddler section of Nate Silver’s Five Thirty Eight web site. Here’s a cut-and-paste of the problem.
Mar 25, 2017
Steve Simon

 

PheKB. A knowledge base for discovering phenotypes from electronic health records

*Recommendation
2017
Informatics
Some of the work I am doing right now could be characterized as discovering phenotypes from electronic health records. So when one of my co-workers mentioned this database…
Mar 24, 2017
Steve Simon

 

Medicare Claims Synthetic Public Use Files (SynPUFs)

*Blog post
2017
Datasets
The Centers for Medicare & Medicaid Services (CMS) provides researchers with access to Medicare claims data, which is a wonderful resources. But you have to sign a…
Mar 23, 2017
Steve Simon

 

Conducting Clinical Research

*Recommendation
2017
Research design
This is a website associated with a very nice book on the pragmatic aspects of running a clinical trial. I came across this site because I was looking for a simple example…
Mar 12, 2017
Steve Simon

 

Are systematic overviews reliable?

*Blog post
2017
Systematic overviews
Dear Professor Mean, I’m helping a student with a piece of work and he described systematic reviews as being reliable. I’m troubled by this on a number of fronts.
Feb 25, 2017
Steve Simon

 

Text Mining with R

*Blog post
2017
Data science
R software
This is an O’Reilly book (cute animal on the cover is a rabbit) that is available online for free. It’s a great resource for someone just getting started with text mining.
Feb 23, 2017
Steve Simon

 

Cases and cohorts and controls, oh my!

*Blog post
2017
Observational studies
Some asked a question about a retrospective study where you have a control cohort matched to a case cohort so the cohorts are similar on important (potentially confounding)…
Feb 17, 2017
Steve Simon

 

R and SQL Server 2016

*Blog post
2017
R software
SQL
I have not viewed this video yet, but it comes from a good friend. There is a substantial effort at Microsoft to better integrate the R programming language and their…
Feb 2, 2017
Steve Simon

 

i2b2 Design Document. Ontology Management (ONT) Cell

*Recommendation
2017
i2b2
I’m digging into some of the complexities of i2b2, especially in the concept path that shows how a particular piece of information in the electronic health record fits into…
Jan 30, 2017
Steve Simon

 

TSHS Resource Portal

*Recommendation
2017
Datasets
Teaching resources
The Teaching of Statistics in the Health Sciences (TSHS) section of the American Statistical Association has put together a set of resources for teachers including several…
Jan 30, 2017
Steve Simon

 

How to run your first Bayesian analysis using jags software in R

*Blog post
2017
Bayesian statistics
Incomplete page
Someone wanted to know how to run a Bayesian data analysis for a two group longitudinal study. There are several ways you can do this, but I had to confess I did not have an…
Jan 28, 2017
Steve Simon

 

Looking inside the brains of scientists

*Blog post
2017
Hypothesis testing
I found an interesting research study that shows what happens inside the brains of scientists as they view statistical graphs of the type commonly used in peer-reviewed…
Jan 28, 2017
Steve Simon

 

Statistical Issues Seen in Non-Statistics Proposals

*Recommendation
2017
Grant writing
If you are writing a research grant, there are a lot of statistical issues that you need to consider. This guide, prepared by the American Statistical Association…
Jan 24, 2017
Steve Simon

 

Guidelines for Assessment and Instruction in Statistics Education College Report 2016

*Recommendation
2017
Teaching resources
As a community, we statisticians have known for a long time that we do not teach that introductory level class in Statistics as well as we should. This guideline list the…
Jan 24, 2017
Steve Simon

 

Another example of pipes in R

*Blog post
2016
R software
I am using pipes in R (the magrittr package) a lot recently. It reduces the number of errors due to nested functions, among other things. I’ve given a simple example before…
Dec 29, 2016
Steve Simon

 

A personal biography

*Blog post
2016
Personal details
I got in touch with a colleague from my days at Bowling Green State University. That was in the 1980s and my life had changed substantially since those days. While I have…
Dec 26, 2016
Steve Simon

 

When differing versions of R packages matter

*Blog post
2016
R software
When you use R, you are using a program that is constantly evolving. The user-contributed packages are also evolving as well. Normally this is not that big a deal. But…
Dec 19, 2016
Steve Simon

 

Why secondary data analysis takes a lot longer

*Blog post
2016
Human side of statistics
Observational studies
Someone posted a question noting that most of the statistical consulting projects that they worked on finished in a reasonable time frame, a few were outliers. They took a…
Dec 17, 2016
Steve Simon

 

Defining Urban and Rural Areas in U.S. Epidemiologic Studies

*Recommendation
2016
Geocoding
I’m somewhat new to geocoding. One of the first things you might be interested in, if you have geographic data, is an indicator as to whether a certain address, zip code, or…
Dec 2, 2016
Steve Simon

 

About those awful election predictions

*Blog post
2016
Probability concepts
If you were on Mars for the past few days, you may not have noticed that Donald Trump has won the election. There has been a lot of commentary lately about how badly the…
Nov 10, 2016
Steve Simon

 

Practical advice for analysis of large, complex data sets

*Recommendation
2016
Human side of statistics
This is a nice compilation of issues that you should be concerned. The examples are mostly from things that interest Google, but you will find this advice itself is useful…
Nov 10, 2016
Steve Simon

 

A simple example of pipes in R

*Blog post
2016
R software
At the Joint Statistical Meetings this year, I learned a lot about recent developments in R, and not so recent developments that I was totally clueless about. One of those…
Nov 8, 2016
Steve Simon

 

Small group presentations using screen sharing tools

*Blog post
2016
Presenting research
I received a suggestion for the Kansas City R Users Group to use screen sharing tools. I am going to experiment with this a bit. Here are two tools worth trying.
Nov 7, 2016
Steve Simon

 

Misunderstanding autism

*Blog post
2016
Ethics in research
A friend of mine posted an inspiring story published in the Washington Post. Unfortunately, it did not inspire me, but rather made me worried about how often we…
Nov 3, 2016
Steve Simon

Drawing the perfect circle

*Blog post
2016
Cheat sheet
R software
I have an R cheat sheet, How Big Is Your Graph, that explains how to measure the size of various features of your graph in R. This blog post illustrates how you can use some…
Oct 31, 2016
Steve Simon

 

Rotating text in an R graph

*Blog post
2016
Cheat sheet
R software
I have an R cheat sheet, How Big Is Your Graph, that explains how to measure the size of various features of your graph in R. This blog post illustrates how you can use some…
Oct 31, 2016
Steve Simon

 

Independent consulting and the cold call

*Blog post
2016
Human side of statistics
There’s been some more discussion about getting started as an independent statistical consultant. One person is ready to hang their shingle and proposes to “find a niche I…
Oct 26, 2016
Steve Simon

 

Those darn commas in SQL

*Blog post
2016
SQL
I should know better, but I made a rookie mistake with SQL that took a long time for me to fix. It’s one of those detail oriented things and if you aren’t detail oriented…
Oct 25, 2016
Steve Simon

 

What do you hate most about independent consulting

*Blog post
2016
Human side of statistics
Someone on the Statistical Consulting forum mentioned that she is going to become an independent consultant when she graduates and wanted to find out from people who are…
Oct 25, 2016
Steve Simon

 

A Tutorial on Loops in R

*Recommendation
2016
R software
Teaching resources
This is a very clear, but also very detailed explanation of the for, while, and repeat loops along with the concept of vectorization. A great resource for beginners.
Oct 20, 2016
Steve Simon

 

Where Do You Run Your R Scripts?

*Recommendation
2016
R software
SQL
I’m an experienced R programmer trying to learn a little about SQL. One of my good friends who lives totally in the database world (I call her the Teradata Queen) shared a…
Oct 20, 2016
Steve Simon

 

Oracle Dates and Times

*Recommendation
2016
Dates
SQL
I’m working with R and SQL. Some of the work uses SQLite, and some of the work uses Oracle. There are subtle differences between the two, and for that matter between any two…
Oct 18, 2016
Steve Simon

 

What greedy means to a geek

*Blog post
2016
Statistical computing
I’ve run across the term “greedy” in several work related contexts, so I thought it might be worth explaining what it means.
Oct 16, 2016
Steve Simon

 

One small grant for me, one giant leap for Biostatisticians

*Blog post
2016
Professional details
Teaching resources
I’m so busy these days that it is silly to take on anything new, but I found an opportunity for a small research grant that I might want to submit a proposal for.
Oct 3, 2016
Steve Simon

 

Published methodological quality of randomized controlled trials does not reflect the actual quality assessed in protocols

*Recommendation
2016
Systematic overviews
When evaluating a series of research articles, you often have to assess the quality of the individual papers based on the type of blinding, for example. What do you do if…
Sep 28, 2016
Steve Simon

 

By the skin of my teeth

*Blog post
2016
Professional details
I have to brag a bit. I’m working part-time at Kansas University Medical Center (along with a couple other part-time jobs) and my boss asked me two weeks ago if I was…
Sep 23, 2016
Steve Simon

 

Turning off large blocks of an R Markdown document

*Blog post
2016
R software
When you’re running a large and complicated program using R Markdown, you can use the CACHE option to save a lot of time. CACHE will notice if a program chunk has stayed the…
Sep 13, 2016
Steve Simon

 

Diverse Perspectives on a Flipped Biostatistics Classroom

*Recommendation
2016
Teaching resources
This article is a synthesis of a panel discussion at the 2014 Joint Statistical Meetings on the flipped classroom. The article discusses it solely from the perspective of…
Sep 6, 2016
Steve Simon

 

Merging in dplyr is a lot faster

*Blog post
2016
Data management
R software
At the Joint Statistics Meetings, I found out that the advantages of some of the new libraries for data manipulation (like dplyr and tidyr) go beyond just the flexibility of…
Sep 6, 2016
Steve Simon

 

Organizing data in spreadsheets

*Recommendation
2016
Data management
I have some guidance on how to organize data (written back in 1999), but these guidelines are far superior. To be honest, you should use a database for anything more than…
Sep 1, 2016
Steve Simon

 

What I need from statisticians

*Recommendation
2016
Important statisticians
This interview with Nate Silver was conducted shortly after his keynote address at the 2013 Joint Statistical Meetings. I was at those meetings, but was stuck in a class (a…
Sep 1, 2016
Steve Simon

 

The FAIR Guiding Principles for scientific data management and stewardship

*Recommendation
2016
Data sharing
I’ve always been supportive of efforts to share data. For me, it’s a bit selfish, because I want to find interesting real world examples to use in teaching and on my web…
Aug 25, 2016
Steve Simon

 

Tibbles (Tibbles are a modern take on data frames)

*Recommendation
2016
R software
I’m an old dog R programmer who tends to rely on features of R that were available 10 years ago (an eternity for computers). But it’s time for this old dog to learn new…
Aug 15, 2016
Steve Simon

 

10 Easy Steps to a Complete Understanding of SQL

*Recommendation
2016
SQL
This page outlines some of the fundamental properties of SQL programming that you need to know as you start learning SQL. For example, SQL is a declarative language, meaning…
Aug 15, 2016
Steve Simon

 

Changing the font size in R

*Blog post
2016
Presenting research
R software
This is one of those obvious things that’s not obvious when you need it most. Suppose I’m doing a demo of R for a group like our wonderful Kansas City R Users Group. I want…
Aug 8, 2016
Steve Simon

 

Changing the font size in RStudio

*Blog post
2016
Presenting research
R software
Suppose you’re giving a talk and using R Studio. You want to make the fonts a bit larger so your audience can read them. It’s easy to do, once you know where to look.
Aug 8, 2016
Steve Simon

 

dplyr and pipes: the basics

*Recommendation
2016
R software
One of the recent developments in R that I was unaware of until I attended some talks at the Joint Statistical Meetings was the use of dplyr and pipes. It’s an approach to…
Aug 7, 2016
Steve Simon

 

Hadley Wickham, the Man Who Revolutionized R

*Recommendation
2016
Important statisticians
R software
Hadley Wickham has written many popular R packages, so many that they are sometimes referred to as the “Hadleyverse.” This is a nice biography that emphasizes the impact…
Aug 7, 2016
Steve Simon

 

Bad examples of data analysis are bad examples to use in teaching

*Blog post
2016
Critical appraisal
Teaching resources
I’m on various email discussion groups and every once in a while someone sends out a request that sounds something like this.
Aug 7, 2016
Steve Simon

 

Recommendation: The Analysis of Biological Data, 2nd Edition

*Blog post
2016
Teaching resources
I have not seen this book, but it comes highly recommended by Frank Harrell, which is good enough for me.
Aug 3, 2016
Steve Simon

 

Enrichment design studies should enhance signals of effectiveness.

*Recommendation
2016
Research design
I noticed several talks at the JSM 2016 on enrichment designs. I was only very vaguely familiar with what this meant, so I did a quick Google search. I found this very nice…
Aug 3, 2016
Steve Simon

 

The Importance of Reproducible Research in High-Throughput Biology

*Blog post
2016
Data quality
Informatics
Research design
I have not viewed this video yet, but have attended a similar talk and read a similar research paper by Keith Baggerly. His general message is that large biological and…
Aug 3, 2016
Steve Simon

 

Never consult by email if you can help it

*Blog post
2016
Human side of statistics
Consulting is always a back and forth process and often you will find yourself re-working things because of communication problems. That’s okay, but keep in mind that…
Jul 27, 2016
Steve Simon

 

Simple string substitutions

*Blog post
Incomplete page
2016
R software
I had to make a rather complex string substitution for a project and I thought it would help to briefly review some simpler string substitution examples in R. You can find…
Jul 15, 2016
Steve Simon

 

100+ Interesting Data Sets for Statistics

*Recommendation
2016
Datasets
This list starts out with a data set of 216,930 previous Jeopardy questions and goes from there. Not everything suggested is easily amenable for statistical analysis, but…
Jun 26, 2016
Steve Simon

 

Institute for Digital Research and Education - Statistical Computing

*Recommendation
2016
Datasets
This is a wonderful site, but for some reason, it is difficult to find. The Institute for Digital Research and Education (IDRE) at UCLA has put together some wonderful…
Jun 24, 2016
Steve Simon

 

So you’re thinking about a systematic overview

*Blog post
2016
Research design
Systematic overviews
If you are designing a systematic overview, you should talk to a statistician early in the process. There are lots of little things that you can do to make your research…
Jun 17, 2016
Steve Simon

 

Handling date-times in R

*Recommendation
2016
Data management
R software
Dates in R, like dates in any other software package, are tricky to work with. Here’s a nice guide that will help you get started.
Jun 15, 2016
Steve Simon

 

So you’re thinking about a pilot study

*Blog post
2016
Pilot studies
Research design
If you are designing a retrospective chart review, you should talk to a statistician early in the process. There are lots of statistical issues that you must think about…
Jun 14, 2016
Steve Simon

 

Can you recommend an introductory book on Bayesian Statistics

*Blog post
2016
Bayesian statistics
Teaching resources
I got an email asking for a recommendation for an introductory book on Bayesian Statistics from someone who recently graduated from our program. It’s kind of a difficult…
Jun 13, 2016
Steve Simon

 

Recommendation: Ten Simple Rules for Effective Statistical Practice

*Recommendation
Incomplete page
2016
Human side of statistics
This article has good general advice about how to run a statistical analysis, such as Rule 1: Statistical Methods Should Enable Data to Answer Scientific Questions.
Jun 10, 2016
Steve Simon

 

Introduction to R, Monday, August 8 through Friday, August 12, 2016

*Blog post
2016
R software
I will be teaching a one semester hour class at UMKC, Introduction to R (MEDB 5505) on Monday, August 8, 2016 through Friday, August 12, 2016. It runs from 9am to noon on…
Jun 1, 2016
Steve Simon

 

Minimum standards for a github repository

*Blog post
2016
Statistical computing
Using a github repository is new to me, and I need to document some things that may be obvious to more experienced programmers. Here are, as far as I understand it, the…
May 31, 2016
Steve Simon

 

Too many different prior choices for the hierarchical beta binomial model

*Blog post
2016
Bayesian statistics
I’m interested in studying how Bayesian hierarchical models work and I want to start with what seems like the simplest case, the hierarchical beta-binomial model. It’s…
May 31, 2016
Steve Simon

 

Understanding the lasso regression model

*Blog post
2016
Linear regression
R software
I wrote a program in R Markdown that shows how the lasso regression model works. It has too many pictures to be easily ported to this blog, so I’ll share a link to a pdf file…
May 25, 2016
Steve Simon

 

Pretty good work for a part-timer

*Blog post
2016
Professional details
I had to provided some documentation for my supervisor on what I had done in the past year (May 2015 through April 2016). It’s a very brief summary, but it’s still pretty…
May 23, 2016
Steve Simon

 

Trying to save time in R ends up costing me time

*Blog post
2016
R software
Sometimes you end up trying to be so clever that you out-clever yourself. This happened to me today in R. I tried something that was supposed to save me time and it ended up…
May 18, 2016
Steve Simon

 

Examining the storage format for sparse matrices in R

*Blog post
Incomplete page
2016
Data science
R software
I’ve been working with sparse matrices a bit for my work with the Greater Plains Collaborative. They are a very useful way of storing matrices where most of the entries are…
May 16, 2016
Steve Simon

 

A megabyte is not a million bytes

*Blog post
2016
R software
Statistical computing
Sometimes you forget things. Here’s an example.
May 12, 2016
Steve Simon

 

So you’re thinking about a complex survey analysis (created 2016-05-10).

*Blog post
2016
Complex survey
I’m helping someone who is looking at a secondary data analysis that involves a complex sampling schemes. This means that the survey used cluster sampling, and/or stratified…
May 10, 2016
Steve Simon

 

Which R package should I use?

*Blog post
2016
R software
Working with R is great in that if anything has been done in Statistics, there is an R package that will do it. The problem is that sometimes there are four packages that…
May 10, 2016
Steve Simon

 

So you’re thinking about a retrospective chart review

*Blog post
2016
Research design
If you are designing a retrospective chart review, you should talk to a statistician early in the process. There are lots of statistical issues that you must think about…
May 2, 2016
Steve Simon

 

Bayesian computing with INLA

*Recommendation
2016
Bayesian statistics
Longitudinal data
Multilevel models
R software
This page promotes a new approach to a broad class of models (spatio-temporal models, latent variable models, mixed models) using a fast approximation to the Bayesian…
Apr 28, 2016
Steve Simon

 

Calculating 90 day readmission rates

*Blog post
2016
Longitudinal data
Secondary data analysis
Someone asked me how to calculate a 90 day readmission rate from a large database. It’s a tricky problem because for many databases, it requires you to examine the data from…
Apr 27, 2016
Steve Simon

 

Interpretation of Changes in Health-related Quality of Life: The Remarkable Universality of Half a Standard Deviation

*Blog post
2016
Clinical importance
I’ve typically mocked the use of effect sizes in research, but perhaps I need to be a bit more open minded. This paper looked at the “minimally important difference” (note…
Apr 18, 2016
Steve Simon

 

Using version control through git, github, and R Studio

*Blog post
2016
Statistical computing
I’m definitely “old school” when it comes to programming, but there comes a time when even this old dog needs to learn a new trick. I decided yesterday to use version…
Apr 17, 2016
Steve Simon

 

Some simple examples of single imputation

*Blog post
2016
Missing data
I wanted to use R to show some simple approaches to imputing missing values. These approaches are difficult to support because they require that you make some questionable…
Apr 17, 2016
Steve Simon

 

Some open source Kaplan Meier curves

*Blog post
2016
Incomplete page
Survival analysis
I’m giving a talk on the Kaplan-Meier survival curve and wanted to show and interpret a few real examples from the open source literature.
Apr 10, 2016
Steve Simon

 

Reporting and methodological quality of sample size calculations in cluster randomized trials could be improved: a review

*Recommendation
2016
Multilevel models
Sample size justification
The sample size justification for a cluster randomized trial is messy. It requires the use of an intra-class correlation or something similar (the authors use the term…
Mar 30, 2016
Steve Simon

 

The number of subjects per variable required in linear regression analyses

*Recommendation
2016
Linear regression
Sample size justification
There are several rules of thumb out there about how many subjects that you need for a multiple linear regression model. Most of these rules look at the ratio of subjects…
Mar 30, 2016
Steve Simon

 

Is my odds ratio zero or infinity?

*Blog post
2016
Measuring benefit and risk
I know you told me that when one of the row probabilities in a two by two table is 0% or if one of the row probabilities is 100%, then the odds ratio is either 0 or…
Mar 30, 2016
Steve Simon

 

The biggest statistics papers of all time

*Blog post
2016
Writing research papers
I’m giving a short talk about the Kaplan-Meier curve and found out an interesting fact about the 1958 paper by Edward Kaplan and Paul Meier that introduced this curve. It…
Mar 26, 2016
Steve Simon

 

The perils of shortening a survey

*Blog post
2016
Survey design
Dear Professor Mean, I’m trying to publish a research study that involves some survey data, but the peer-reviewer is complaining about something I did. There was a scale…
Mar 22, 2016
Steve Simon

 

Do we really need to teach all this math stuff?

*Blog post
2016
Teaching resources
I got tagged in a Facebook post about an article criticizing the emphasis on math in high school and that proposes replacing some of the more theory based courses like…
Mar 9, 2016
Steve Simon

 

My current work at the Greater Plains Collaborative

*Blog post
2016
Human side of statistics
I’m spending a fair amount of time over the next few months working with Russ Waitman and the Greater Plains Collaborative (GPC). It’s an interesting job so far, and one of…
Mar 9, 2016
Steve Simon

 

PLOS ONE 2015 Reviewer Thank You

*Blog post
2016
Professional details
Writing research papers
I reviewed a paper for PLOS One in 2014 and got a nice acknowledgment, but I also reviewed a paper for the same journal in 2015. Here’s the acknowledgment for that…
Mar 8, 2016
Steve Simon

 

The data structure in i2b2

*Blog post
2016
Statistical computing
I’m working with the Greater Plains Collaborative on a research project and my work requires me to understand the underlying data structure of a system known as i2b2. It’s…
Mar 3, 2016
Steve Simon

 

Selection of controls in case-control studies

*Recommendation
2016
Observational studies
I’m working on a project where the researchers need a case-control study, though they may not know that yet. I want to show them what a case-control study gives them that…
Feb 29, 2016
Steve Simon

 

The need for documentation standards

*Blog post
2016
Statistical computing
I’m working in a team programming environment and I would have to characterize the quality of the documentation as uneven. I’m going to make the case for having detailed…
Feb 25, 2016
Steve Simon

 

The problem with incentivizing

*Blog post
2016
Grant writing
I came across a question, “How does your institution incentivize researchers to write more grants?” that was posted a while ago. I felt it was too late to respond directly…
Feb 23, 2016
Steve Simon

 

Recent (and not so recent) advances in statistical computing

*Blog post
2016
Statistical computing
I’m giving a talk to the Statistics students at the University of Central Missouri. Here’s the title and abstract of my talk.
Feb 22, 2016
Steve Simon

 

My latest short biography

*Blog post
2016
Professional details
I am giving yet another talk and wanted to take some time to update my earlier short biography.
Feb 18, 2016
Steve Simon

 

Searching through a mess of files

*Blog post
2016
Statistical computing
I am working on a project that has a series of files in R and R Markdown, and I need to track down where a particular function was originally defined. In Unix based systems…
Feb 16, 2016
Steve Simon

 

Business essentials that you need to know before starting your career as an independent statistical consultant

*Blog post
2016
Human side of statistics
I am giving a presentation on the business essentials that you need to know before you start a career in independent statistical consulting. Here is a summary of what I’ll…
Feb 14, 2016
Steve Simon

 

Calculating power for a test of association in a two by two table

*Blog post
2016
Sample size justification
A colleague was curious to see the formulas behind the power calculations done by many statistical software programs and online calculators. In particular, she wanted to see…
Feb 5, 2016
Steve Simon

 

Simulating power for a test of association in a two by two table

*Blog post
2016
Incomplete page
Sample size justification
In an earlier blog post, I slogged through the calculation of power for a test of association in a two by two table. You can also approximate power using a simulation. It is…
Feb 5, 2016
Steve Simon

 

A rant about the reader pays model of publication

*Blog post
2016
Writing research papers
Something came up in our department about a predatory pay for access journal that was soliciting support. All the appropriate warnings were made (there’s a nice explanation…
Feb 4, 2016
Steve Simon

 

How detailed should I make my data analysis plan.

*Blog post
2016
Research design
Dear Professor Mean, I could use some advice on defining and following analysis plans for research proposals. I can see how in well-trodden research, where the nuances of…
Feb 3, 2016
Steve Simon

 

The Survey Statistician

*Recommendation
2016
Survey design
The International Association of Survey Statisticians (IASS) has a twice-yearly newsletter that talks about meetings and events sponsored by the association, informal…
Feb 3, 2016
Steve Simon

 

Information about the Great Plains Collaborative Breast Cancer Study

*Blog post
2016
Professional details
I’m starting a new project as an independent consultant. Normally, I talk very little on my blog about specific projects that I work for, but this work is for a group, the…
Jan 28, 2016
Steve Simon

 

The Coin Flip: A Fundamentally Unfair Proposition

*Recommendation
2016
Randomization
A flip of a coin does not result in an exact 50-50 chance of heads or tails. It depends a lot on how the coin is flipped, of course, but there is a bias. This article…
Jan 25, 2016
Steve Simon

 

The Empirical Evidence of Bias in Trials Measuring Treatment Differences

*Recommendation
2016
Critical appraisal
Randomization
When I wrote a book about Evidence Based Medicine back in 2006, I talked about empirical evidence to support the use of certain research methodologies like blinding and…
Jan 25, 2016
Steve Simon

 

My research interests

*Blog post
2016
Professional details
I got an email from someone at UMKC with the title, Director of Undergraduate Research. She was
Jan 22, 2016
Steve Simon

 

Two grumpy editorials at NEJM

*Blog post
2016
Data sharing
Quality improvement
I don’t have time to follow the journals as closely as I should, but I was shocked to find two very nasty editorials in recent issues of the New England Journal of Medicine.…
Jan 22, 2016
Steve Simon

 

ENCODE: Encyclopedia of DNA Elements

*Recommendation
2016
Datasets
The genetics research community should be lauded for the openness with which they share research data. You can find numerous data sources that are free and without ANY…
Jan 19, 2016
Steve Simon

 

UMKC is now offering Qualtrics software to researchers

*Blog post
2016
Survey design
One of the UMKC internal publications, UMatters, had a brief article about Qualtrics. What is Qualtrics, and why is UMKC offering it to researchers?
Jan 19, 2016
Steve Simon

 

Odds ratio with a zero in the table

*Blog post
2016
Ask Professor Mean
Measuring benefit and risk
I have a data set where 94 out of 100 patients with cancer have activation of a gene, while 0 out of 50 of the controls have activation. When I compute the odds ratio, I get…
Jan 19, 2016
Steve Simon

 

My book chapter on R

*Blog post
2016
Professional details
I was asked by a colleague to write a chapter for a book he was editing, Big Data Analysis for Bioinformatics and Biomedical Discoveries. My chapter was “R for Big Data…
Jan 13, 2016
Steve Simon

 

Lyndon B. Johnson Space Center job opening for a GS-14 Statistician

*Recommendation
2016
Human side of statistics
I get a lot of emails mentioning job openings and I normally delete them unread. This one caught my eye, not because I wanted to apply for it, but because it illustrates how…
Jan 13, 2016
Steve Simon

 

Preprints and the Ingelfinger rule

*Blog post
2016
Open source
Writing research papers
The same blog that I highlighted below had a commentary about how clinicians almost never publish pre-prints of their work. This is in contrast to other fields, most notably…
Jan 6, 2016
Steve Simon

 

A Grant Submission New Year’s Resolution

*Recommendation
2016
Grant writing
Michael Lauer, the Deputy Director for Extramural Research at the United States National Institutes for Health shows some interesting statistics on when people submit grants…
Jan 6, 2016
Steve Simon

 

Points to consider on switching between superiority and non-inferiority

*Recommendation
2015
Hypothesis testing
One of the most confusing aspects of medical research is the difference between non-inferiority and superiority trials. This article explains in simple terms what the two…
Dec 20, 2015
Steve Simon

 

The COMPare Project

*Recommendation
2015
Critical appraisal
Publication bias
One of the many problems with medical publications is that researchers will choose which outcomes to report based on their statistical significance rather than their…
Dec 7, 2015
Steve Simon

 

Differences between information in registries and articles did not influence publication acceptance

*Recommendation
2015
Critical appraisal
Publication bias
Here’s a research article tackling the same problem of changing outcome measures after the data is collected. Apparently, this occurs in 66 of the 226 papers reviewed here…
Dec 7, 2015
Steve Simon

 

The Likelihood Ratio Slide Rule poster submission

*Blog post
2015
Diagnostic testing
Professional details
I submitted a poster to the 2015 UMKC Faculty Research Symposium (described at the UMKC Office of Research Support website). It’s a chance to show off some of the work I did…
Dec 3, 2015
Steve Simon

 

A book review of my first book

*Blog post
2015
Critical appraisal
Professional details
I wrote a book about nine years ago and interest in it has largely died down. Perhaps I should write a second edition. Anyway, I ran across a book review that I had not seen…
Dec 2, 2015
Steve Simon

 

Safeguarding Patients in Clinical Trials with High Mortality Rates

*Blog post
2015
Blinding in research
Early stopping
Ethics in research
This is an article the I would trot out if anyone tried to argue that a Data Safety and Monitoring Board should, like the investigators, be blinded as to treatment status…
Dec 2, 2015
Steve Simon

 

My Google Scholar profile

*Blog post
2015
Professional details
A while back, I set up a publication list in Google Scholar. It tracks the number of citations received by each article that I published. One of my articles has a massive…
Nov 16, 2015
Steve Simon

 

Quote: That’s not an experiment

*Quotation
2015
Critical appraisal
Referring to anecdotal data: “That’s not an experiment you have there, that’s an experience.” Sir Ronald A. Fisher. I do not know where I found this quote. Sorry!
Oct 29, 2015
Steve Simon

 

Recommendation: Clinical trials: discerning hype from substance

*Recommendation
2015
Randomization
I was attending a short course taught by Susanne May on clinical trials (very good, by the way) and she mentioned an interesting publication. It talks about the “random…
Oct 29, 2015
Steve Simon

 

How many research subjects

*Blog post
2015
Sample size justification
Here’s a quote from yours truly.
Oct 13, 2015
Steve Simon

 

Nonlinear regression for the difference of two exponentials

*Blog post
2015
incomplete page
nonlinear regression
R software
Rmarkdown graphs
I wanted to provide an overview of how you analyze a classic nonlinear regression model. It is a difference of two exponential functions. This nonlinear function is used…
Oct 5, 2015
Steve Simon

 

How big is my graph?

*Blog post
2015
Broken link
Incomplete page
R software
When you are drawing a graph in R, sometimes you have to check how big things are before you can do anything else. There are many different ways of measuring size. Here are…
Oct 5, 2015
Steve Simon

 

PS: Power and Sample Size Calculation

*Recommendation
2015
Sample size justification
Someone stopped by today with a power calculation and I asked what software they used. They showed me something I had not seen before, a program developed by the Department…
Sep 24, 2015
Steve Simon

 

A non-technical answer to why we need Markov Chain Monte Carlo

*Blog post
2015
Accrual problems
Bayesian statistics
Someone was looking for examples of illustrative examples to help explain to people without a statistical background how MCMC methods can be applied to help solve real world…
Sep 21, 2015
Steve Simon

 

Finding interesting peer-reviewed articles that illustrate statistical tests

*Blog post
2015
Teaching resources
Someone asked how do you find peer-reviewed articles that use simple statistical tests so your students can see the structure of papers that report on statistical analyses.…
Sep 16, 2015
Steve Simon

 

Research vs Quality Improvement

*Recommendation
2015
Ethics in research
I ran across a one page handout in PDF format that discussed the difference between research and quality improvement. It was written from the perspective of the IRB…
Sep 16, 2015
Steve Simon

 

What problems does introversion cause for a statistical consultant?

*Blog post
2015
Human side of statistics
Someone posed an interesting question on the Statistics Consulting message board of the American Statistical Association. To paraphrase, her question was what sort of…
Sep 8, 2015
Steve Simon

 

My H-index

*Blog post
2015
Professional details
It’s a silly number, perhaps, but I tried to calculate my H-index today. The H-index lists your publications in order from the most cited to the least cited and then finds…
Aug 20, 2015
Steve Simon

 

R number 6 in IEEE 2015 Top Programming Languages, Rising 3 Places

*Recommendation
2015
R software
This Revolutions blog talks about a fairly rigorous evaluation of popular programming languages done by the Institute of Electrical and Electronics Engineers (known by most…
Aug 20, 2015
Steve Simon

 

The pros and cons of cluster randomized trials

*Blog post
2015
Multilevel models
Research design
I’m helping out a researcher with sample size justification for a cluster randomized trial. I may write a bit about that soon, but in the process of double checking my…
Aug 13, 2015
Steve Simon

 

I want to learn (learn more) about R

*Blog post
2015
R software
Teaching resources
I get a lot of questions along the lines of “I want to learn R, can you help me?” or “Where can I learn more about R?” or some other variation. These questions are usually…
Aug 7, 2015
Steve Simon

 

Files for my R class

*Blog post
2015
Being updated
Here is a brief abstract.
Jul 29, 2015
Steve Simon

 

How do you select variables for a risk adjusted model?

*Blog post
2015
Risk adjustment
I was helping a colleague write a response to a reviewer who asked about a risk adjusted model. How did you select the variables for adjustment? He/she speculated that we…
Jul 16, 2015
Steve Simon

 

Some interesting publicly available data sets

*Blog post
2015
Datasets
I’ve been looking for a few interesting data sets for use as teaching examples. I wanted data associated with peer-reviewed publications. It’s a difficult and tedious…
Jul 15, 2015
Steve Simon

 

This is Statistics promotional toolkit

*Blog post
2015
Human side of statistics
The American Statistical Association is promoting careers in statistics though a new campaign titled “This is Statistics”. They just added some very nice promotional…
Jun 30, 2015
Steve Simon

 

My research contributions to Evidence Based Medicine

*Blog post
2015
Professional details
The U.S. National Institutes of Health (NIH) has a new biosketch format where they ask you to summarize “up to five of your most significant contributions to science.”…
Jun 3, 2015
Steve Simon

 

My research contributions to patient accrual models

*Blog post
2015
Professional details
The U.S. National Institutes of Health (NIH) has a new biosketch format where they ask you to summarize “up to five of your most significant contributions to science.”…
Jun 3, 2015
Steve Simon

 

Informed consent in a study without human subjects

*Blog post
2015
Ethics in research
Do you need an informed consent form if you are not conducting research on human subjects?
Jun 1, 2015
Steve Simon

 

A short biography for the person introducing me

*Blog post
2015
Professional details
I get requests for a short biography from people asked to introduce me. I like to store these on my website so that I can refer to them and update them. Here’s the latest…
Jun 1, 2015
Steve Simon

 

My research contributions to numerical accuracy

*Blog post
2015
Professional details
The U.S. National Institutes of Health (NIH) has a new biosketch format where they ask you to summarize “up to five of your most significant contributions to science.”…
May 30, 2015
Steve Simon

 

My research contributions to reproductive toxicology

*Blog post
2015
Professional details
The U.S. National Institutes of Health (NIH) has a new biosketch format where they ask you to summarize “up to five of your most significant contributions to science.”…
May 30, 2015
Steve Simon

 

I am now a number in the ORCID database

*Blog post
2015
Professional details
Life in the world of research is complicated, but it gets worse when you have a relatively common last name like “Simon.” There are thousands of research publications…
May 27, 2015
Steve Simon

 

Developing Grant Proposals: Guidelines for Statisticians Collaborating Under Limited Resources

*Blog post
2015
Grant writing
This article provides guidance for developing the “statistical considerations” section of a research grant. I normally do not use that term, and suggest separate sections on…
May 26, 2015
Steve Simon

 

PLOS ONE 2014 Reviewer Thank You

*Recommendation
2015
Writing research papers
I don’t do nearly enough peer reviewing, in part because it is a thankless, anonymous task. But one journal editor sent me a nice email pointing out that my name was listed…
May 20, 2015
Steve Simon

 

Can I replace missing values with zero?

*Blog post
2015
Missing data
I have a large data set from a household budget survey with 20,000 records. When I calculate the mean for some of the variables, there are some missing values. Sometimes it…
May 18, 2015
Steve Simon

 

Validating a test of diabetes

*Blog post
2015
Diagnostic testing
Sample size justification
I have a simple algorithm that determines whether a person is diabetic or not. I am planning on validating this algorithm, and I need to know how many patients I need to…
May 11, 2015
Steve Simon

 

Training on how to write a grant

*Blog post
2015
Grant writing
I usually do not recommend commercial products, as I know most of you have very limited funds. But when it comes to grants, you should consider paying for good training. The…
May 8, 2015
Steve Simon

 

What not to say in the limitations and alternative strategies section of your grant

*Blog post
2015
Grant writing
I was reviewing a grant and the section on limitations and alternative strategies started off with the following sentence, “We do not anticipate any major limitations in…
May 6, 2015
Steve Simon

 

Improving Bioscience Research Reporting: The ARRIVE Guidelines for Reporting Animal Research

*Recommendation
2015
Critical appraisal
A lot of people have adapted and updated the CONSORT Guidelines to reporting clinical trials to handle other types of research. One of these adaptations is the ARRIVE…
Apr 30, 2015
Steve Simon

 

Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm

*Recommendation
2015
Graphical display
Many scientists rely on bar graphs and line graphs that effectively reduce your data to a single mean per group. Even with the addition of error bars, the whole process…
Apr 30, 2015
Steve Simon

 

An Introduction to Social Media for Scientists

*Recommendation
2015
Human side of statistics
It’s easy to mock social media, but these are important tools not just for sharing pictures of the food your eating but for informing your colleagues about your research.…
Apr 30, 2015
Steve Simon

 

Restoring invisible and abandoned trials

*Blog post
2015
Publication bias
Too much research data goes unreported, leading to a serious distortion of the evidence base that clinicians need to make intelligent medical decisions. The authors of this…
Apr 16, 2015
Steve Simon

 

Equations using MathType

*Blog post
2015
Presenting research
Obsolete page
NOte: This page is obsolete. I am currently using Markdown, MathJax, and TeX to generate equations.
Apr 12, 2015
Steve Simon

Examining relationships in R

*Blog post
2015
R software
Rmarkdown graphs
I’m giving a talk for the Kansas City R Users Group on how to get a preliminary impression of relationships between pairs of variables. Here is the R code and output that I…
Apr 3, 2015
Steve Simon

 

Acceptable response rates

*Blog post
2015
Observational studies
Survey design
I review a lot of observational studies in the literature, and I am concerned about the response rates and when they fall so low that they tend to produce problems with…
Mar 30, 2015
Steve Simon

 

Nonparametric tests for multifactor designs

*Blog post
2015
Logistic regression
Nonparametric tests
I want to run nonparametric tests like the Kruskal-Wallis test and the Friedman test for a setting where there may be more than one factor. Everything I’ve seen for these…
Mar 30, 2015
Steve Simon

 

Forget confounding, and think of things in terms of covariate imbalance

*Blog post
2015
Risk adjustment
Someone noted in a passing comment in their email that they found the term “confounding” to be difficult and confusing. I’ve been doing this stuff for over thirty years, but…
Mar 4, 2015
Steve Simon

 

Editorial (Basic and Applied Social Psychology)

*Recommendation
2015
Bayesian statistics
Hypothesis testing
Recommended does not always mean that I agree with what’s written. In this case. It means that this is something that is important to read because it offers an important…
Feb 24, 2015
Steve Simon

 

Rich Data, Poor Data

*Recommendation
2015
Statistical models
Nate Silver emphasizes an important point about when statistical models can really shine: when there is a rich source of data and lots of opportunities to test the…
Feb 24, 2015
Steve Simon

 

Missing values in R talk

*Blog post
2015
R software
I’m talking a bit about missing values in R this afternoon for the Kansas City R Users Group. Here is what I’ll be talking about.
Feb 7, 2015
Steve Simon

 

New R Package: cdcfluview

*Recommendation
2015
R software
I work a lot with secondary datasets and I’m always looking for new and interesting resources. There is a CDC site that tracks flu reports and with a bit of effort, you can…
Feb 3, 2015
Steve Simon

 

P-Values

*Recommendation
2015
Hypothesis testing
Randall Munroe, author of the xkcd comic strip, will often comment on Statistics. This cartoon shows how p-values are typically interpreted.
Feb 3, 2015
Steve Simon

 

The answer is 17 years, what is the question. Understanding time lags in translational research

*Blog post
2015
Critical appraisal
A widely quoted statistic is that it takes 17 years for research to find it’s way from the initial discovery to clinical practice. That statistic has always bothered me. How…
Jan 15, 2015
Steve Simon

 

Tessera. Open source environment for deep analysis of large complex data

*Recommendation
2015
Data science
R software
I have not had time to preview this software, but it looks very interesting. It takes large problems and converts them to a form for parallel processing not by changing the…
Jan 12, 2015
Steve Simon

 

Analyzing ordinal salary categories

*Blog post
2015
Logistic regression
Ordinal data
I have three variables: physicians (%), dentists (%), and salary categories. I want to know if there is a difference in the percentage of physicians and dentists in each…
Jan 8, 2015
Steve Simon

 

Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD): the TRIPOD Statement

*Recommendation
2015
Writing research papers
If you are writing up a paper that uses a complex regression model (complex meaning multiple independent variables), you need to document information that allows the reader…
Jan 8, 2015
Steve Simon

 

Report on Survey Participation Refusals

*Blog post
2014
Exclusions in research
The American Association for Public Opinion Research (AAPOR) convened a task force to address the increasing tendency of people to refuse to respond (as is their right) to a…
Dec 23, 2014
Steve Simon

 

Meta-analysis of ordinal data

*Blog post
2014
Systematic overviews
Dear Professor Mean, I would like to conduct a meta-analysis of several studies. The data in these studies were evaluated using an ordinal scoring system coded as 0,1,2,3.…
Dec 15, 2014
Steve Simon

 

In search of justification for the unpredictability paradox

*Recommendation
2014
Critical appraisal
Randomization
Systematic overviews
This is a commentary on a 2011 Cochrane Review that found substantial differences between studies that were adequately randomized and those that were not adequately…
Dec 11, 2014
Steve Simon

 

Requiring fuel gauges. A pitch for justifying impact evaluation sample size assumptions

*Recommendation
2014
Grant writing
Sample size justification
This blog entry from the International Initiative for Impact Evaluation talks about the deficiency in many research proposals sent to that organization. They rely too much…
Dec 10, 2014
Steve Simon

 

What Teachers Should Know about the Bootstrap: Resampling in the Undergraduate Statistics Curriculum

*Recommendation
2014
Bootstrap
Tim Hesterberg has been a long time advocate of the use of the bootstrap. In this article, he provides a nice general overview of the bootstrap with examples of how it works…
Nov 24, 2014
Steve Simon

 

I need a clinical research coordinator

*Blog post
2014
Human side of statistics
Dear Professor Mean, I run a clinic and have a company interested in having my patients participate in a clinical trial. They tell me that I need to have a clinical research…
Nov 18, 2014
Steve Simon

 

Cox regression in R

*Blog post
2014
R software
Survival analysis
I wanted to show a couple of Cox proportional hazards regression models in R for a talk I am giving for the R users group.
Nov 1, 2014
Steve Simon

 

More Kaplan-Meier curves in R

*Blog post
2014
R software
Survival analysis
I found a larger data set and wanted to show how you could use the Kaplan Meier curves as a preliminary screen of some categorical and continuous variables in a larger and…
Nov 1, 2014
Steve Simon

 

Kaplan-Meier curves in R

*Blog post
2014
R software
Survival analysis
I am giving a talk about using R for survival analysis and I wanted to talk first about the Kaplan-Meier curve and how you might draw it in R.
Oct 31, 2014
Steve Simon

 

Communicating Statistical Findings to Consulting Clients Operating in a Decisionmaking Climate: Best and Worst Practices

*Recommendation
2014
Human side of statistics
There were a large number of excellent talks at the 2014 Joint Statistics Meeting. This session discusses practical issues associated with communication. Although I did not…
Aug 19, 2014
Steve Simon

 

Sample size of 12 per group rule of thumb for a pilot study

*Blog post
2014
Pilot studies
Sample size justification
This study is (sadly) not available for free on the Internet - but it is still worth highlighting here. Steven Julious provides some justification for the use of twelve…
Aug 13, 2014
Steve Simon

 

What is the probability of a probability of one

*Blog post
2014
Bayesian statistics
Someone wrote asking me about a variation of the “Rule of Three”. This rule says that if you observe zero events out of n, an upper 95% confidence limit for n is…
Jul 24, 2014
Steve Simon

 

An example of a simple sample size justification

*Blog post
2014
Sample size justification
Someone asked me for a sample size justification for a study involving a historical control group of 30 patients and a treatment group of unspecified size. I thought it…
Jul 22, 2014
Steve Simon

 

A brief abstract of my research interests

*Blog post
2014
Grant writing
I attended a working group meeting for researchers interested in Chem bio Defense applications. They asked each attendee to write a brief abstract of their research…
Jul 14, 2014
Steve Simon

 

Special issue–Using Big Data to Transform Care

*Recommendation
2014
Data science
Ethics in research
The July 2014 issue of Health Affairs is devoted entirely to “big data”.<U+00A0> The articles provide a general overview to big data - several applications of big data - big…
Jul 14, 2014
Steve Simon

 

Simple longitudinal data sets to illustrate data management

*Blog post
2014
Datasets
Longitudinal data
Missing data
I am working on a class that will teach basic data management and graphics using the R programming language with parallel classes in SPSS and SAS. On the third or fourth day…
Jul 7, 2014
Steve Simon

 

Software on my computer

*Blog post
2014
Obsolete page
Professional details
This page is obsolete. I am keeping because I have fun looking back at things I did many years ago.
Jun 30, 2014
Steve Simon

 

Adapt the personal statement on your biosketch to the specific grant

*Blog post
2014
Grant writing
When you are asked to prepare a biosketch for a research grant, you should adapt the personal statement of the biosketch to highlight the specific skills that you have that…
Jun 28, 2014
Steve Simon

 

Who is your authorized official?

*Blog post
2014
Broken link
Grant writing
This page is obsolete. I am keeping it around for nostalgic reasons.
Jun 27, 2014
Steve Simon

 

A biased sample of car speeds

*Blog post
2014
Survey design
Dear Professor Mean, I read a newspaper report about speed limits and how few people obeyed them. A reporter decided to collect some hard data and drove exactly at the speed…
Jun 18, 2014
Steve Simon

 

MLPowSim software

*Recommendation
2014
Longitudinal data
Sample size justification
This site provides description of a free software package - MLPowSim, that calculates power for complex random effects models. It was developed by the Centre for Multilevel…
Jun 16, 2014
Steve Simon

 

Sample size for a study of reproducibility

*Blog post
2014
Measuring agreement
Sample size justification
Dear Professor Mean: I am using a risk stratification tool for patients presenting to the ED with chest pain. This has been a well validated tool in the ED, but I want to…
Jun 16, 2014
Steve Simon

 

Comparisons within randomised groups can be very misleading

*Recommendation
2014
Longitudinal data
In studies with a baseline, examining the decline exclusively within the treated group, or examining the decline in the treated group and then separately examining the…
Jun 10, 2014
Steve Simon

 

What should go into a data codebook

*Blog post
2014
Data management
Before you start your data entry, you should create a data codebook. If you don’t have a data codebook when you hand your data over to someone else, take the time to create…
May 31, 2014
Steve Simon

 

History of SPSS

*Blog post
2014
Statistical computing
I’m helping to put together three separate classes, Basic data management and analysis with R [SAS / SPSS]. As part of these classes, I need to discuss the history of these…
May 31, 2014
Steve Simon

 

FDA: R OK for drug trials

*Recommendation
2014
R software
This blog post reviews a presentation by Jae Brodowsky, a statistician with the U.S. Food and Drug Administration that put to bed the rumor that FDA will only accept…
May 30, 2014
Steve Simon

History of R

*Blog post
2014
R software
I’m helping to put together three separate classes, Basic data management and analysis with R, SAS, SPSS. As part of these classes, I need to discuss the history of these…
May 30, 2014
Steve Simon

 

History of SAS

*Blog post
2014
SAS software
Statistical computing
I’m helping to put together three separate classes, Basic data management and analysis with R [SAS / SPSS]. As part of these classes, I need to discuss the history of these…
May 30, 2014
Steve Simon

 

Course proposal on setting up an independent consulting practice

*Blog post
2014
Human side of statistics
I was asked to prepare a proposal on a short course about consulting for an upcoming Statistics conference. I had talked about this in an earlier blog post. Here is the…
May 13, 2014
Steve Simon

 

A review of methods for missing data

*Recommendation
2014
Missing data
This is a nice summary of the advantages and disadvantages of various methods for handling missing values.
May 6, 2014
Steve Simon

 

Meet John Gawalt, Director of the National Center for Science and Engineering Statistics

*Recommendation
2014
Important statisticians
This is a brief interview with John Gawalt, the new director of the National Center for Science and Engineering Statistics within the National Science Foundation.
May 5, 2014
Steve Simon

 

8 tips for doing data visualization right.

*Recommendation
2014
Graphical display
This slide show includes some examples of really bad (and a few really good) graphics with some explanations of general principles for data display.
May 3, 2014
Steve Simon

 

Using BUGS within the R programming environment

*Blog post
2014
Bayesian statistics
R software
I am giving a talk today for the Kansas City R Users group about BUGS (Bayes Using Gibbs Sampler). I have already written extensively about BUGS and the interface to BUGS…
May 3, 2014
Steve Simon

 

Data doesn’t speak for itself

*Recommendation
2014
Graphical display
Presenting research
This blog post explains that you can’t just put a graph up on a screen and immediately expect people to understand it. You need to provide critical context to help your…
May 1, 2014
Steve Simon

 

Not all scientific studies are created equal

*Blog post
2014
Observational studies
This video gives a non-technical overview of the strengths and weaknesses of observational studies.
May 1, 2014
Steve Simon

 

Proposed outline for How to Start and Run an Independent Statistical Consulting Business

*Blog post
2014
Human side of statistics
There has been a bit of discussion on submitting a proposal to teach a class on running an independent consulting business for an upcoming statistics conference. I think it…
May 1, 2014
Steve Simon

 

Pmean: The IRB questions my sample size calculation

*Blog post
2014
Sample size justification
I got a question today from someone submitting a research protocol to the Institutional Review Board (IRB). The IRB had some concerns about the power calculation. In…
Apr 30, 2014
Steve Simon

 

The random risks of randomised trials

*Recommendation
2014
Randomization
This is an overview of some of the ethical controversies associated with randomization. It includes an interesting story of an early trial by Archie Cochrane that raised a…
Apr 28, 2014
Steve Simon

 

Stretching an already borderline sample size

*Blog post
2014
Sample size justification
I was working with a client who had a limited population of medical residents to choose from, and it would be a struggle to get even 60 of them. The primary outcome was…
Apr 16, 2014
Steve Simon

 

Two data sets illustrating the analysis of continuous variables

*Blog post
2014
Datasets
I am looking for good teaching examples that will illustrate methods for univariate and bivariate analysis of continuous variables. Here are two publicly available data sets…
Apr 15, 2014
Steve Simon

 

Using statistical design principles to plan a Monte Carlo analysis – part 2

*Blog post
2014
Statistical computing
I’ve been working more on a Monte Carlo study of various Bayesian estimators and it makes me think about certain principles that we statisticians use in experimental design…
Apr 14, 2014
Steve Simon

 

Post hoc sample size calculations

*Blog post
2014
Post hoc power
Someone asked about references on post hoc power calculation on the MEDSTATS email discussion group and, as we all know, this is a very bad idea. But someone offered a…
Apr 10, 2014
Steve Simon

 

More on Big Data Training for the Scientific Workforce

*Recommendation
2014
Data science
The United States National Institutes for Health is very interested in big data and has developed a working group, Big Data to Knowledge (BD2K). This blog post from Sally…
Apr 8, 2014
Steve Simon

 

Predicting clinical trial results based on announcements of interim analyses

*Blog post
2014
Early stopping
If you’ve ever been involved with interim reviews of clinical trials on a DSMB (Data Safety and Monitoring Board), you will be warned about the importance of…
Apr 6, 2014
Steve Simon

 

Quote: Excel’s graphics can be great. The problem occurs

*Quotation
2014
Graphical display
…when people assume that the Excel output is enough. I think of all the research papers in economics where the authors must have spent dozens of hours trying all sorts of…
Apr 3, 2014
Steve Simon

 

Estimating the efficiency of a completely randomized block design

*Blog post
2014
Analysis of variance
I needed to look up a formula for the estimating the relative efficiency to a completely randomized block design to a design without blocking.
Mar 12, 2014
Steve Simon

 

Using statistical design principles to plan a Monte Carlo analysis

*Blog post
2014
Statistical computing
I want to run a Monte Carlo analysis of various Bayesian estimators to see how they perform when the prior distribution is “wrong”. I’m like everyone else–I just plunge in…
Mar 9, 2014
Steve Simon

 

Comparing two vectors with possible missing values

*Blog post
2014
R software
I want to compare two vectors in R that have the same length and identify where, if anywhere, that the two vectors don’t match. It sounds like an easy thing to do, but…
Mar 6, 2014
Steve Simon

 

foreach: Foreach looping construct for R

*Blog post
2014
R software
This is an add-on package for R that allows you to separate a lengthy programming task into different pieces, each of which can run on a separate core of your multi-core…
Mar 5, 2014
Steve Simon

 

Meet Charles J. Rothwell, Director, National Center for Health Statistics

*Recommendation
2014
Important statisticians
This is a brief interview with the director of the National Center for Health Statistics, a statistical agency for the United States government that produces many nationally…
Mar 5, 2014
Steve Simon

 

Qualifications for Teaching an Introductory Statistics Course

*Recommendation
2014
Teaching resources
The American Statistical Association and the Mathematical Association of America published a joint statement on the qualifications that a college teacher would need in order…
Mar 5, 2014
Steve Simon

 

plotrix: Various plotting functions

*Recommendation
2014
Graphical display
R software
R has a lot of nice plotting features built in - but this add-on package adds some more - especially the ability to designate a break in one of your axes.
Feb 26, 2014
Steve Simon

 

A guide to the line style arguments for R graphics

*Recommendation
2014
Graphical display
R software
Melissa Clarkson created a very nice two page PDF file that shows very clearly the sometimes subtle difference in how various line style arguments work in R. Highly…
Feb 25, 2014
Steve Simon

 

NIH is interested in big data

*Blog post
2014
Data science
The National Institutes of Health has shown a recent interest in “big data.” You can define big data in several ways, but a common characteristic is the three V’s. Big data…
Feb 24, 2014
Steve Simon

 

How many months should you wait before re-testing?

*Blog post
2014
Research design
I got a question that I had never heard before, and it sort of is a statistics question and sort of isn’t. A researcher was comparing two methods of training residents in a…
Feb 21, 2014
Steve Simon

 

Why Coincidences, Miracles And Rare Events Happen Every Day.

*Blog post
2014
Probability concepts
This is an interview with David Hand, the author of a new book, The Improbability Principle: Why Coincidences, Miracles and Rare Events Happen Every Day. The discussion…
Feb 20, 2014
Steve Simon

 

Summary of my research interest in patient accrual in clinical trials.

*Blog post
2014
Accrual problems
My boss at UMKC (I’m part-time at UMKC and part-time independent statistical consultant) asked me for one of those “summarize the research you’ve been working on” so she…
Feb 15, 2014
Steve Simon

 

Why randomized controlled trials fail but needn’t: 2. Failure to employ physiological statistics, or the only formula a clinician-trialist is ever likely to need (or understand!)

*Recommendation
2014
Sample size justification
This is a classic article about the relationship between signal, noise, sample size, and confidence. It provided pragmatic guidance on designing a trial to make the best use…
Feb 10, 2014
Steve Simon

 

Quote: Because statistics has too often been presented

*Quotation
2014
Teaching resources
Because statistics has too often been presented as a bag of specialized computational tools, with morbid emphasis on calculation, it is no wonder that survivors of such…
Feb 6, 2014
Steve Simon

 

Troubleshooting Public Data Archiving: Suggestions to Increase Participation

*Recommendation
2014
Ethics in research
I’ve always been a big fan of data sharing, mostly for selfish reasons. I like to see interesting data sets and use them as teaching examples and on my website. There are…
Feb 3, 2014
Steve Simon

 

Will 2015 be the Beginning of the End for SAS and SPSS?

*Blog post
2014
SAS software
R software
This is a provocative title but the actual blog post itself is far more nuanced. By several measures, R is becoming more and more popular, but that hardly means that SAS or…
Jan 29, 2014
Steve Simon

 

Savage Chickens cartoon on optimistic graphs

*Recommendation
2014
Graphical display
I checked the licensing rules before posting this. Thank you, Doug Savage, at savagechickens. A direct link to this cartoon is here.
Jan 28, 2014
Steve Simon

 

Calculating statistics that have limitations

*Blog post
2014
Hypothesis testing
Someone asked what you should do if you get a request to compute a p-value on a post hoc analysis. In general, any statistic computed on a post hoc analysis is likely to be…
Jan 27, 2014
Steve Simon

 

The Next Billionaire: A Statistician Who Changed Medicine.

*Recommendation
2014
Important statisticians
This is a nice profile of Dennis Gillings, a statistician who started a small company in the 1980s with only 5 employees. This company, Quintiles, is now the world’s largest…
Jan 24, 2014
Steve Simon

 

No power calculation for a Phase II trial

*Blog post
2014
Sample size justification
There was an discussion on the message board for the Statistical Consulting Section of the American Statistical Association started by a question about a Phase II trial. The…
Jan 22, 2014
Steve Simon

 

The dget function in R is very slow

*Blog post
2014
R software
I made another rookie mistake in R. I have a program in R that needed to store a large matrix for later re-use. You can use the dput function to put a copy of the matrix out…
Jan 22, 2014
Steve Simon

 

I have turned off the comments feature on all pages

*Blog post
2014
Website details
This page is obsolete (it refers to a version of my website developed under WordPress). I am keeping it around for sentimental reasons.
Jan 17, 2014
Steve Simon

 

Large randomized controlled trials are ready for retirement

*Recommendation
2014
Randomization
Dean Ornish contributes his response to a series of invited essays on the topic “What Scientific Idea is Ready for Retirement?” His choice is the large randomized controlled…
Jan 17, 2014
Steve Simon

 

Survey of Attitudes Toward Statistics (SATS)

*Recommendation
2014
Survey design
In an earlier post, I had recommended the Statistics Attitude Survey. There is a very similar survey available, The Survey of Attitudes Toward Statistics (SATS), created by…
Jan 17, 2014
Steve Simon

 

Resources for a workshop in R

*Blog post
2014
broken link
obsolete pages
R software
This page is obsolete but I am keeping it around for nostalgic reasons.
Jan 15, 2014
Steve Simon

 

Statistics Attitude Survey scale

*Recommendation
2014
Survey design
Dennis Roberts has a webpage with several attitude scales that have been published in the peer-reviewed literature. The fifth one on the list is a Statistics Attitude Scale…
Jan 15, 2014
Steve Simon

 

Git can facilitate greater reproducibility and increased transparency in science

*Recommendation
2014
Statistical computing
This article talks about git, a version control system for computer programmers, and how it can be used by researchers to improve the ability of others to understand and to…
Jan 13, 2014
Steve Simon

 

What I like about R

*Blog post
2014
R software
I’m helping out with a beginner’s R workshop and I might say a few words at the beginning about what I like about R. There are three big things, really.
Jan 10, 2014
Steve Simon

 

What’s so good about early anyway.

*Recommendation
2014
Diagnostic testing
This blog entry notes how easy it is to fool yourself into thinking that a screening program is doing well because it finds problems “early while you still have a chance.”…
Jan 9, 2014
Steve Simon

 

Recommendation: A Quick Guide for Developing Effective Bioinformatics Programming Skills

*Recommendation
2014
Informatics
R software
So you want to be a bioinformatitian? I can barely pronounce the word myself. But it’s a growing field with lots of interesting opportunities. This paper explains some of…
Jan 7, 2014
Steve Simon

 

Resolutions for this blog for 2014

*Blog post
2014
website details
I took a couple of weeks off from everything work related, including this blog. I’m back today. My goal in 2014 is to try to post about 6 entries per week on this blog, with…
Jan 7, 2014
Steve Simon

Some simple examples of manipulating the axes in a graph

*Blog post
2014
Data visualization
Rmarkdown graphs
I want to start with a simple artificial example, a cubic function. With this simple function, you will see different ways of displaying information on the x and y axes.
Jan 1, 2014
Steve Simon

The qqplot

*Blog post
2014
Checking assumptions
Linear regression
R software
Rmarkdown graphs
Many statistical procedures are based on the assumption that your data has a normal distribution. The normal probability plot is a useful graphical tool for asessing this…
Jan 1, 2014
Steve Simon

 

Comparison of Logistic Regression versus Propensity Score When the Number of Events Is Low and There Are Multiple Confounders

*Recommendation
2013
Risk adjustment
Propensity scores represent an intriguing alternative method to reduce the impact of confounding variables, especially when there are multiple potential confounding…
Dec 20, 2013
Steve Simon

 

Sample size for comparing two diagnostic tests

*Blog post
2013
Sample size justification
I had a client come in with a sample size question. It involved the comparison of two diagnostic tests to a gold standard. There a couple of different ways to attack the…
Dec 18, 2013
Steve Simon

 

DataMind website

*Recommendation
2013
R software
DataMind is a website offering free tutorials for the R programming language and tools that let you develop your own tutorials based on R Markdown. I have not tested any of…
Dec 12, 2013
Steve Simon

 

Study Development (Kansas City area resource)

*Recommendation
2013
Grant writing
This is an excellent local resource for those of you in the Kansas City area. They have guidance on coming up with a study idea, finding funding, and identifying study…
Dec 12, 2013
Steve Simon

 

Claims lacking specificity are meaningless

*Blog post
2013
Critical appraisal
I recently encountered a claim about the unlimited applications for a new statistical model. I, for one, tend to view “unlimited applications” as a negative comment rather…
Dec 10, 2013
Steve Simon

 

Use equal sign for assignmentin R?

*Recommendation
2013
R software
I learned R back when the only way to assign a value was with the <- operator. For example, if you were computing the hypotenuse of a triangle, you’d use c <- sqrt(a^2+b^2).…
Dec 9, 2013
Steve Simon

 

Is Possibility Theory better than Probability Theory?

*Blog post
2013
Bayesian statistics
Someone on a LinkedIn group posted a question about “Possibility Theory.” The question itself had a lot of hype, claiming that “time has expired for Probability Theory.”…
Dec 9, 2013
Steve Simon

 

Simple example of Fourier transform

*Blog post
2013
Being updated
This page is a bit confusing. The link to the earlier version uses the name wavelet.html, but the text shows a simple Fourier transform. Is there also a simple example of…
Dec 7, 2013
Steve Simon

 

Any other comments? Open questions on questionnaires. A bane or a bonus to research?

*Recommendation
2013
Survey design
This is a classic reference that is worth re-posting. No one seems to know what to do about those pesky open-ended questions you see on a survey. This article offers…
Dec 5, 2013
Steve Simon

 

The cost of a bad prediction

*Blog post
2013
Bayesian statistics
Paul Krugman wrote up an interesting application of Bayes Theorem on his blog on the New York Times. I want to adapt his example and expand it a bit.
Dec 4, 2013
Steve Simon

 

How confidence intervals become confusion intervals.

*Recommendation
2013
Confidence intervals
The desire among researchers for a black and white dichotomy between “significant” and “not significant” results leads to a lot of unnecessary confusion.
Dec 3, 2013
Steve Simon

 

The riddle of experience vs. memory

*Recommendation
2013
Human side of statistics
There are a series of experiments that show that your memory of an event is colored more by the experience at the end of the event. This leads to some fascinating…
Dec 2, 2013
Steve Simon

 

Five Fridays in a month

*Blog post
2013
Being updated
Earlier versions are here and here.
Dec 1, 2013
Steve Simon

 

You can now register for an account on my blog.

*Blog post
2013
Obsolete post
This post is obsolete, but I am keeping it around for nostalgic reasons.
Nov 30, 2013
Steve Simon

 

Row over breast cancer screening shows that scientists bring some subjectivity into their work.

*Recommendation
2013
Systematic overviews
This is a classic reference that reminds us that even with all the objective methods developed for systematic overviews, there is still a core of choices that are largely…
Nov 29, 2013
Steve Simon

 

Two questions you should always ask at the end of a consulting session

*Blog post
2013
Human side of statistics
There was a discussion in the ASA Consulting Section forum about how to avoid “failures” in consulting. Failures can mean a variety of things, missed deadlines, incorrect…
Nov 29, 2013
Steve Simon

 

Revised standards for statistical evidence

*Recommendation
2013
Bayesian statistics
This article compares the Bayesian standard of what constitutes convincing evidence to the frequentist reliance on the p-value to measure evidence. The author concludes that…
Nov 28, 2013
Steve Simon

 

Blog is up and ready for testing

*Blog post
2013
Obsolete pages
This post is obsolete, but I decided to keep it around for nostalgic reasons.
Nov 27, 2013
Steve Simon

 

Twenty tips for interpreting scientific claims

*Recommendation
2013
Critical appraisal
This article provides advice to non-statisticians on how to interpret claims made in the peer-reviewed literature.
Nov 27, 2013
Steve Simon

 

Testing an R function

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 2, 2013
Steve Simon

 

Hedging your bets on an informative prior

*Blog post
2013
Being updated
Earlier versions are here and here.
Sep 26, 2013
Steve Simon

 

Can I focus on a subset of conditions in my experiment

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 10, 2013
Steve Simon

 

Running JAGS from R, a simple example

*Blog post
2013
Being updated
Earlier versions are here and here.
Sep 4, 2013
Steve Simon

 

Confusion about BUGS

*Blog post
2013
Broken link
Bayesian statistics
R software
Note 2024-05-28: This page notes some of the problems with obsolescence of software, but some of the links that document the obsolescence are themselves obsolete. You may…
Sep 3, 2013
Steve Simon

 

Developing a computer program using modern methods

*Blog post
2013
Being updated
Earlier versions are here and here.
Sep 3, 2013
Steve Simon

 

I get a letter published in the Kansas City Star

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 26, 2013
Steve Simon

 

Resource for statisticians called as legal experts in a trial

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 14, 2013
Steve Simon

 

Data sources for a proposed course on secondary data analysis

*Blog post
2013
Teaching resources
I am giving a talk at the Joint Statistical Meetings (JSM) in Toronto. I’m still tweaking the slides just a few hours before the talk. The title is “Data sources for a…
Aug 7, 2013
Steve Simon

 

Sample chapter: The first three steps in a descriptive data analysis

*Blog post
2013
Being updated
buttonology (uncountable)
Aug 1, 2013
Steve Simon

 

Calculating predicted probabilities from a logistic regression model

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 31, 2013
Steve Simon

 

R code for estimating the duration of a clinical trial with a fixed sample size

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 29, 2013
Steve Simon

 

R code for estimating the sample size of a clinical trial with a fixed duration

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 29, 2013
Steve Simon

R code for estimating the sample size of a clinical trial with a fixed duration

*Blog post
2013
Accrual problems
Bayesian statistics
Please note that I have not had a chance to test the code on this updated page.
Jul 29, 2013
Steve Simon

 

How do you compute an adjusted probability?

*Blog post
2013
Being updated
Earlier versions are here and here.
Apr 26, 2013
Steve Simon

 

The confidence interval for my odds ratio is too narrow!

*Blog post
2013
Being updated
Earlier versions are here and here.
Apr 23, 2013
Steve Simon

 

Deciphering a non-linear curve

*Blog post
2013
Being updated
You can find an earlier version of this page on my website.
Apr 9, 2013
Steve Simon

 

Counting squares

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 2, 2013
Steve Simon

 

A complex subgroup definition

*Blog post
2013
SPSS software
I got a question about a complex definition of a subgroup for data in SPSS. I’ve changed a few details, but the gist of the question goes like this:
Mar 25, 2013
Steve Simon

 

Placing the mind of a statistician into software

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 19, 2013
Steve Simon

 

What does it really mean to say that a mean of a large number of variables is approximately normal

*Blog post
2013
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 14, 2013
Steve Simon

 

Elbow model for accrual

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2012
Steve Simon

 

Elbow model for accrual

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2012
Steve Simon

 

Mixture of two binomial distributions

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2012
Steve Simon

 

What you should look for in a statistical consultant

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2012
Steve Simon

 

A single wildly large value makes you less confident that the mean of your data is large

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 12, 2012
Steve Simon

 

Animations in R

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 8, 2012
Steve Simon

 

Analyzing data from the National Hospital Ambulatory Care Survey

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 4, 2012
Steve Simon

 

Data sharing

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 21, 2012
Steve Simon

 

Lasso talk

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 1

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 2

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 3

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 4

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 5

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Lasso talk, figure 6

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 5, 2012
Steve Simon

 

Mapping my runs in R

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 10, 2012
Steve Simon

 

Are you qualified to make that comment?

*Blog post
2012
Being updated
Earlier versions are here and here.
Oct 8, 2012
Steve Simon

 

Don’t write your own questionnaire

*Blog post
2012
Being updated
Someone asked for general guidance on how to write your own questionnaire. I wrote a rather negative response.
Oct 4, 2012
Steve Simon

 

Debating the validity of snowball sampling

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 1, 2012
Steve Simon

 

Borderline p-values

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 19, 2012
Steve Simon

 

When should I use the Fisher’s Exact Test and when should I use the Chi-Square Test

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 19, 2012
Steve Simon

 

What’s the name of the test for comparing two proportions?

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 12, 2012
Steve Simon

 

Data management in R versus SAS

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 27, 2012
Steve Simon

 

Whiskers in a boxplot

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 27, 2012
Steve Simon

 

Parsing information in an XML file

*Blog post
2012
Being updated
Note: This page was written before I knew about the stringr package in R. It simplifies the code and makes it easier to understand. If I find the time, I would like to…
Jul 20, 2012
Steve Simon

 

The secret to great wealth is …

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 16, 2012
Steve Simon

 

Counting pages at my old and new websites

*Blog post
2012
Obsolete pages
This page is obsolete, but I am keeping it around, mostly for nostalgic reasons.
Jul 3, 2012
Steve Simon

 

New post

*Blog post
2012
Being updated
Here is a brief abstract.
Jun 22, 2012
Steve Simon

 

An interesting mistake I made in BUGS

*Blog post
2012
Being updated
I am just learning how to run BUGS software. I’ve used WinBUGS, which is a stand-alone program for Windows, and OpenBUGS, which is an Open Source version that runs on…
May 22, 2012
Steve Simon

 

Reviewing how the binomial and negative binomial distributions work

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 17, 2012
Steve Simon

 

A simple example of change of variable

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 15, 2012
Steve Simon

 

A fishy story about randomization

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 12, 2012
Steve Simon

 

Statistical distributions borrowed from Wikipedia

*Blog post
2012
Being updated
Earlier versions are here and here.
May 2, 2012
Steve Simon

 

Accrual with refusals, exclusions, or dropouts

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 22, 2012
Steve Simon

 

The simple accrual model, redefined

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 19, 2012
Steve Simon

 

BUGS model for the simple Poisson accrual model

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 18, 2012
Steve Simon

 

Fitting the homogenous accrual model in BUGS

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 13, 2012
Steve Simon

 

Deriving accrual using the geometric distribution

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 9, 2012
Steve Simon

 

Bad scaling choices for the SPSS ROC curve

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 9, 2012
Steve Simon

 

What’s new

*Blog post
2012
Being updated
I’ve made a lot of updates to my website. Here are some of the recent highlights:
Apr 9, 2012
Steve Simon

 

Iowa talk on accrual

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 3, 2012
Steve Simon

 

Those pesky tab characters

*Blog post
2012
Data management
SPSS software
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 21, 2012
Steve Simon

 

Free consultation means no co-authorship?

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 19, 2012
Steve Simon

 

Why use a Bayesian adaptive trial?

*Blog post
2012
Bayesian statistics
The Bayesian adaptive trial controls the probability of randomizing a patient to each of the proposed dose groups. As data emerges during the study, the probabilities are…
Mar 7, 2012
Steve Simon

 

Making predictions based on just the correlation

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 7, 2012
Steve Simon

 

How sample size calculations are reported in the literature

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 23, 2012
Steve Simon

 

What non-statistical skills do consultants need?

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 18, 2012
Steve Simon

 

Questions for a panel on statistical consulting

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 8, 2012
Steve Simon

 

Percentage of care that does not have a medical basis

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 6, 2012
Steve Simon

 

Promoting your consulting career in the era of web 2.0

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 27, 2012
Steve Simon

 

Honorable mention for my R code on accrual

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 25, 2012
Steve Simon

 

Arguing with the material in an ethics training program

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 12, 2012
Steve Simon

 

What to report when SPSS says the p-value is zero

*Blog post
2012
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 9, 2012
Steve Simon

 

Is sample size justification really different for animal studies compared to human studies?

*Blog post
2012
Ask Professor Mean
Sample size justification
Dear Professor Mean, I’ve spent my entire career (so far) in developing statistical analysis plans for human subjects research. Recently, a neuroscientist who performs…
Jan 6, 2012
Steve Simon

 

Post hoc power persists because peer-reviewers demand it

*Blog post
2012
Being updated
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Jan 4, 2012
Steve Simon

 

A very silly graph

*Blog post
2012
Being updated
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Jan 1, 2012
Steve Simon

 

Author pays model

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2011
Steve Simon

 

Some thoughts on a backup policy

*Blog post
2011
Being updated
Earlier versions are here and here.
Dec 31, 2011
Steve Simon

 

Definition of translational research

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2011
Steve Simon

 

Review of new James Penston book

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2011
Steve Simon

 

Strange results in KMeans clustering

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 31, 2011
Steve Simon

 

Unrealistic scenarios for sample size calculations

*Blog post
2011
Sample size justification
I’m not a doctor, so when someone presents information to me about the clinically important difference (a crucial component of any sample size justification), I should just…
Dec 20, 2011
Steve Simon

 

Discrepancies in the chisquare test

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 16, 2011
Steve Simon

 

Example abstracts for a training class

*Blog post
2011
Critical appraisal
Teaching resources
I am giving a webinar to a group that is interested in applications of statistics to Alzheimer’s disease and schizophrenia. I wanted to show some real world uses of p-values…
Dec 8, 2011
Steve Simon

 

Justifying the sample size in a qualitative research study

*Blog post
2011
Qualitative research
Sample size justification
I was asked to help justify the sample size for a qualitative research study. When the goals of a study are qualitative, the sample size justification is also qualitative.
Nov 22, 2011
Steve Simon

 

Why is a 20% dropout rate bad?

*Blog post
2011
Being updated
How can we give an evidence based answer about why 20% loss of follow-up in a randomized trial is too much?
Nov 21, 2011
Steve Simon

 

Possible webcast topics for a new client

*Blog post
2011
Teaching resources
I was asked to develop a list of webcast topics for a client working in the pharmaceutical industry. They are listed roughly in priority order for the first half. I have…
Nov 14, 2011
Steve Simon

 

SPSS won’t compute my odds ratio!

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 8, 2011
Steve Simon

 

Looking at another grant opportunity

*Blog post
2011
Being updated
It must be masochism on my part, but I’m looking at writing yet another grant. This grant would go to the Heartland Institute for Clinical and Translational Research and…
Nov 7, 2011
Steve Simon

 

A bunch of univariate nonparametric tests versus a single parametric model

*Blog post
2011
Logistic regression
I’m working on a of weight loss during hospitalization. I’m measuring the percent change in the weight loss from admission to discharge and looking at the factors that…
Nov 3, 2011
Steve Simon

 

Meta-analysis with non-comparable procedures

*Blog post
2011
Being updated
In publications on meta-analysis where vast numbers of papers must be culled from the analyzable dataset due to non-comparable procedures. The resulting smaller sample sizes…
Oct 31, 2011
Steve Simon

 

Lasagna’s Law on patient recruitment

*Blog post
2011
Accrual problems
I sent out a question to an email discussion group asking about documentation of sample size shortfalls in clinical research. Someone suggested that I google “Lasagna’s…
Oct 24, 2011
Steve Simon

 

My entry into the Applications of R in Business Competition

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 20, 2011
Steve Simon

 

Net-accessible resources for group sequential designs

*Blog post
2011
Early stopping
I am trying to locate a good net-accessible resource for the group sequential designs, and sample size re-estimation for adaptive designs. Can you help?
Oct 19, 2011
Steve Simon

 

How you can teach Bayesian methods in an introductory Statistics class and why you should

*Blog post
2011
Bayesian statistics
There’s been a discussion among members of the Statistics in Epidemiology Section of the American Statistical Association about what topics should be covered in an…
Oct 17, 2011
Steve Simon

 

Conditional Frailty Models

*Blog post
2011
Being updated
One of the people I am working with is interested in using gap time analysis with a conditional frailty model. I was impressed with this request and asked her to send any…
Oct 11, 2011
Steve Simon

 

Statistical literacy talk

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 6, 2011
Steve Simon

 

Proposal for session on grant writing

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 4, 2011
Steve Simon

 

What single idea will make the biggest impact on healthcare today

*Blog post
2011
Being updated
Earlier versions are here and here.
Sep 16, 2011
Steve Simon

 

Draft grant submission on patient accrual

*Blog post
2011
Accrual problems
Here’s an early draft of a grant submission on patient accrual. It is in response to PA-11-180, and we would submit this by February 5, 2012. I have made comments to myself…
Sep 13, 2011
Steve Simon

 

Sharing the same classroom for five consecutive years

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 12, 2011
Steve Simon

 

Should I report the univariate or the multivariate logistic regression analysis?

*Blog post
2011
Logistic regression
I have results from four univariate logistic regression models and one multivariate logistic regression model with all four variables. In my univariate analysis, all the…
Sep 7, 2011
Steve Simon

 

Statistics is more than just cutting computer code

*Blog post
2011
Human side of statistics
Someon on LinkedIn asked how to react to a comment like “Statistics is just cutting computer code, right?” Here’s how I responded.
Sep 6, 2011
Steve Simon

 

I can’t get SAS to model the cluster effects in the MEPS data set

*Blog post
2011
Complex surveys
I’m trying to use SAS to analyze data from the Medical Expenditure Panel Survey (MEPS) but when I try to model the cluster effect using proc glimmix, I get an error message.…
Sep 2, 2011
Steve Simon

 

Can I salvage my negative confidence interval

*Blog post
2011
Confidence intervals
I was involved in a small case-control project that was intended to explore some genotypes as predictors of disease progression. We had between 50 and 60 cases and controls…
Sep 2, 2011
Steve Simon

 

What are the assumptions of logistic regression

*Blog post
2011
Logistic regression
Does anyone have a good reference for the assumptions of binary logistic regression? I have a client who has an anonymous reviewer who says his analysis doesn’t meet one of…
Sep 1, 2011
Steve Simon

 

New flat rate for consulting

*Blog post
2011
Professional details
This page is obsolete. I am keeping it around for nostalgic reasons.
Aug 17, 2011
Steve Simon

 

Positive statements about no conflicts of interest

*Blog post
2011
Conflict of interest
There is a lot of confusion about when you can report “No conflict of interest.” You don’t know whether this means that there is no financial relationship with any…
Aug 16, 2011
Steve Simon

 

Banning editorials and clinical reviews from authors with industry ties

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 13, 2011
Steve Simon

 

The advantages of IBM SPSS software

*Blog post
2011
SPSS software
You have a lot of choices for how to do your data analysis. I have found that the best option for most people I work with is to use IBM SPSS software. Here are the main…
Aug 11, 2011
Steve Simon

 

What goes on your business card

*Blog post
2011
Independent consulting
Someone who was about to embark on an independent consulting career asked me what you should put on your business card. My advice was to keep it simple.
Aug 4, 2011
Steve Simon

 

Publicity for your consulting career

*Blog post
2011
Being updated
Human side of statistics
I have been talking about independent consulting a lot at the Joint Statistical Meeting, and I wanted to summarize some of my commentary about publicizing your consulting…
Aug 4, 2011
Steve Simon

 

Using Social Media to promote your consulting career

*Blog post
2011
Independent consulting
I am leading a roundtable discussion of using Social Media to promote your consulting career. Here are some things that I plan to discuss.
Aug 1, 2011
Steve Simon

 

Twelve subjects in a within subject design

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 30, 2011
Steve Simon

 

Validation of OpenEpi software

*Blog post
2011
Statistical computing
I was asked to “validate” a software program called OpenEpi. If you want to validate software, you need to show that it produces correct answers for a variety of test cases.…
Jul 27, 2011
Steve Simon

 

Second invitation to talk about how independent consulting is different

*Blog post
2011
Independent consulting
I have a second invitation to talk on how independent consulting is different in 2012 (send me an email if you’re curious about when and where). I was asked to submit an…
Jul 24, 2011
Steve Simon

 

There’s more than one way to calculate a Fisher’s exact p-value

*Blog post
2011
Measuring benefit and risk
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 21, 2011
Steve Simon

 

Establishing accuracy for a statistical program (created 2011-07-14).

*Blog post
2011
Statistical computing
I’ve been asked to establish that a particular program, OpenEpi, can accurately calculate test statistics for a two by two table. The package appears quite good, and it is…
Jul 14, 2011
Steve Simon

 

Teaching classes for a fee

*Blog post
2008
Being updated
Teaching resources
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 11, 2011
Steve Simon

 

Calculating a confidence interval for a standard deviation

*Blog post
2011
Confidence intervals
Rmarkdown code
Suppose that you had a sample of 80 observations and you computed a standard deviation of those 80 observations. Like any other statistic, the standard deviation will have…
Jul 10, 2011
Steve Simon

 

Software that I use on my computers

*Blog post
2011
Statistical computing
I thought it might be useful to list the software programs that I use on my various laptop computers. That way I can check to see if I have installed the programs that I…
Jun 21, 2011
Steve Simon

 

How much work does that second reviewer have to do in a meta-analysis

*Blog post
2011
Systematic overviews
Someone asked about the process of using a second reviewer in a meta-analysis to abstract data from studies. The rationale for a second reviewer, of course, is to establish…
Jun 20, 2011
Steve Simon

 

Statistical calculators on the web

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jun 17, 2011
Steve Simon

 

Looking for help to test software for monitoring accrual in a clinical trial

*Blog post
2011
Accrual problems
I need some collaborators for a grant I am writing from people who conduct prospective clinical trials. I am working on methods to monitor patient accrual in clinical…
Jun 16, 2011
Steve Simon

 

Small business grant? Maybe not (created 2011-06-16).

*Blog post
2011
Accrual problems
I want to document on this webpage, a general idea of where we might want to submit a grant to continue our work on accrual models. In particular, I was originally leaning…
Jun 16, 2011
Steve Simon

 

How I became a skeptic

*Blog post
2011
Critical appraisal
I’m a big fan of the skeptic movement. If you’re not familiar with this, it is a group of professional and amateur scientists who critically examine claims of fringe science…
Jun 15, 2011
Steve Simon

 

Cartoon about placebos

*Blog post
2011
Being updated
I drew a small cartoon about placebos. I know you think that this is drawn by a professional artist, but I did this. Really!
Jun 14, 2011
Steve Simon

 

Which version of SPSS should you get

*Blog post
2011
SPSS software
I was showing a client how to use their version of SPSS to a variety of different things and when I went to run a logistic regression model, it wasn’t there. Apparently…
Jun 3, 2011
Steve Simon

 

When you’re stuck writing major sections of another person’s grant

*Blog post
2011
Being updated
I was helping someone write a grant when I got that request that I always dread, “Can you write this section of the grant.” I hate those requests for a personal reason–I’d…
Jun 2, 2011
Steve Simon

 

New shortened structure for NIH grants

*Blog post
2011
Writing research grants
I am working on an NIH grant looking at various Bayesian models for accrual. NIH changed the grant proposal format last year to a much shorter proposal. Good for them, I…
Jun 2, 2011
Steve Simon

 

It’s been a quiet year

*Blog post
2011
Professional details
I was asked by my boss to document my scholarly activities for the past year. I used July 1, 2010 through June 30, 2011 as the time frame (I don’t anticipate a lot happening…
Jun 1, 2011
Steve Simon

 

Can prisons randomly assign prisoners without their consent?

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 31, 2011
Steve Simon

 

A simple segmented linear regression model, borrowed from the BUGS manual

*Blog post
2011
Bayesian statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 25, 2011
Steve Simon

 

Bayesian inference on the geometric distribution

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 22, 2011
Steve Simon

 

Using a binary coding trick illustrated by a Car Talk puzzler

*Blog post
2011
Data management
I often need to see how often certain variables and combinations of those variables appear in a data set. If the variable is binary, there is a trick for doing this that is…
May 21, 2011
Steve Simon

 

A simple hierarchical model for the Poisson distribution, borrowed from the BUGS manual

*Blog post
2011
Bayesian statistics
I am interested in various extensions to the simple Bayesian model for accrual that Byron Gajewski and I derived and published in Statistics in Medicine. An important…
May 20, 2011
Steve Simon

 

Promoting your consulting career in the era of Web 2.0

*Blog post
2011
Independent consulting
I was approached by a member of the planning committee for the American Statistical Association Conference on Statistical Practice about giving a talk at that conference.…
May 20, 2011
Steve Simon

 

Yet another biography

*Blog post
2011
Professional details
I’m asked often to provide a short biography that can be used as an introduction to a talk I am giving. Anything that I pass along to an introducer I also post on my…
May 16, 2011
Steve Simon

 

What I’d look for in a new computer

*Blog post
2011
Statistical computing
I am hardly an expert on computing, but I do try to help out when someone asks me about what sort of computer they should buy for statistical analyses. Here are some general…
May 16, 2011
Steve Simon

 

Is it ethical to provide statistical consulting on a disseration to a Ph.D. candidate

*Blog post
2011
Being updated
Someone asked a hypothetical question about consulting assistance for a Ph.D. candidate. Clearly some assistance is okay and the question is when the work becomes so much…
May 11, 2011
Steve Simon

 

How independent consulting is different

*Blog post
2011
Being updated
I am scheduled to be part of a panel discussion titled “Successful Statistical Consulting: The Practicalities.”
May 9, 2011
Steve Simon

 

The importance of being self-critical

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 5, 2011
Steve Simon

 

Why is my standard deviation so small

*Blog post
2011
Descriptive statistics
I am helping someone with a projec that involves (among other things), computing averages of many Likert scale items. A Likert scale has different interpretations, but I use…
May 2, 2011
Steve Simon

 

I can’t find a standard deviation for my power calculations

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 26, 2011
Steve Simon

 

Examples of the difference made by high quality research

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 22, 2011
Steve Simon

 

Can Bayesian methods help with small sample sizes?

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 20, 2011
Steve Simon

 

Resources for Comparative Effectiveness Research

*Blog post
2011
Teaching resources
I attended an interesting webinar on Comparative Effectiveness Research (CER). I always try to take notes during presentations like this, but my notes are often a poor…
Apr 13, 2011
Steve Simon

 

Thinking about the title for my second book

*Blog post
2011
Professional details
As I mentioned on an earlier webpage, Cambridge University Press has agreed to publish my second book. There were some suggestions, including a change in the proposed title…
Apr 11, 2011
Steve Simon

 

Quotes and references from Dr. Harrell

*Blog post
2011
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 7, 2011
Steve Simon

 

Does a wide confidence interval mean that my conclusions are all wrong?

*Blog post
2011
Confidence intervals
My confidence intervals are very wide. I do not know how to explain this. Does this mean that my results are likely to be wrong?
Mar 24, 2011
Steve Simon

 

The nature of advice on email discussion lists

*Blog post
2011
Teaching resources
I participate on several email discussion lists, and someone complained a bit about the advice he was getting. “So my question is if this forum is open for people like me?…
Mar 8, 2011
Steve Simon

 

Macros in Stata

*Blog post
2011
Stata software
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 8, 2011
Steve Simon

 

My special Zotero style

*Blog post
2011
Website details
I use Zotero to produce html code for the “Outside Resource” section of my category pages. It requires a special style which I have adapted.
Feb 22, 2011
Steve Simon

 

I won’t serve on my IRB, but there is a way I can still help.

*Blog post
2011
Ethics in research
I had offered to help out our local IRB but was not careful to clarify how I could help. This resulted in me being appointed as an alternate member of the IRB. That’s not a…
Feb 17, 2011
Steve Simon

 

Good news about my second book proposal

*Blog post
2011
Being updated
I got an email three days ago from my contact at Cambridge University Press. It looks like they want to publish my book!
Jan 1, 2011
Steve Simon

 

Creating LaTex formulas on the fly

*Blog post
2010
Being updated
Writing research papers
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 20, 2010
Steve Simon

 

Location of my UMKC office

*Blog post
2010
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 9, 2010
Steve Simon

 

Using the Poisson distribution for modeling accrual

*Blog post
2010
Accrual problems
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 1, 2010
Steve Simon

 

Closed form solution for homogenous accrual

*Blog post
2010
Being updated
Accrual problems
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 1, 2010
Steve Simon

 

Are certain CAM therapies undeserving of further study

*Blog post
2010
Being updated
Critical appraisal
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 1, 2010
Steve Simon

 

Poem to help you remember the quotient rule

*Blog post
2010
Being updated
Mathematics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 26, 2010
Steve Simon

 

Transforming the parameter also transforms the prior distribution

*Blog post
2010
Bayesian statistics
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 25, 2010
Steve Simon

 

The odds ratio in logistic regression is the opposite of what it should be

*Blog post
2010
Being updated
Logistic regression
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 22, 2010
Steve Simon

 

BUGS is more than just one program

*Blog post
2010
Bayesian statistics
Being updated
I am working on some Bayesian models that use a program called BUGS. BUGS stands for Bayesian Inference Using Gibbs Sampling. There are several ways you can run BUGS, and it…
Nov 19, 2010
Steve Simon

 

Ambiguity in the definition of the exponential distribution

*Blog post
2010
Being updated
Probability distributions
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 16, 2010
Steve Simon

 

The Science-Based Medicine blog defends itself

*Blog post
2010
Being updated
Evidence based medicine
I get a few fan letters from people, which are greatly appreciated, but when I get the rare critical response, I am even more grateful. It doesn’t matter if the criticism is…
Nov 9, 2010
Steve Simon

 

Taking conflict of interest too far

*Blog post
2010
Being updated
Conflict of interest
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 6, 2010
Steve Simon

 

Would you hire someone who knew theory

*Blog post
2010
Being updated
Human side of statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 3, 2010
Steve Simon

 

Justifying the sample size in an equivalence study

*Blog post
2010
Being updated
Sample size justification
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 2, 2010
Steve Simon

 

Work in pharma versus work in academia

*Blog post
2010
Being updated
Human side of statistics
Earlier versions are here and here.
Oct 23, 2010
Steve Simon

 

Reconciling the various ways to calculate power for an ANOVA model

*Blog post
2010
Being updated
Sample size justification
I am trying to reconcile all the different ways that power can be calculated for an ANOVA model. The various formulas are confusing.
Oct 16, 2010
Steve Simon

 

Lost page

*Blog post
2010
Being updated
Mixed models
Earlier versions are here and here.
Oct 12, 2010
Steve Simon

 

Poster presentation at the Missouri Technology conference

*Blog post
2010
Accrual problems
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 4, 2010
Steve Simon

 

If you knew that failure was not an option what would you do

*Blog post
2010
Being updated
Human side of statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 1, 2010
Steve Simon

 

Why the least squares regression line has to pass through XBAR, YBAR

*Blog post
2010
Being updated
Linear regression
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Oct 1, 2010
Steve Simon

 

Putting variable names into a model automatically

*Blog post
2010
Being updated
R software
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Sep 20, 2010
Steve Simon

 

Is there something better than Evidence Based Medicine out there

*Blog post
2010
Being updated
Evidence based medicine
Someone asked me about a claim made on an interesting blog post on the Science Based Medicine blog. The writer of this post, Kimball Atwood, claims that Science Based…
Sep 20, 2010
Steve Simon

 

Oh those pesky interactions!

*Blog post
2010
Being updated
Modeling issues
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Sep 16, 2010
Steve Simon

 

My new twitter account

*Blog post
2010
Being updated
Professional details
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Sep 15, 2010
Steve Simon

 

Can you compute a confidence interval for your p-value

*Blog post
2010
Being updated
Hypothesis testing
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Sep 10, 2010
Steve Simon

 

Using information theory to identify discrepancies within and between text files

*Blog post
2010
Being updated
Information theory
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Sep 2, 2010
Steve Simon

 

Is it ethical to recruit a panhandler

*Blog post
2010
Ethics in research
Someone asked a question about the ethics of approaching a panhandler and sharing information about a research study. I don’t know all the details, but apparently, this…
Sep 1, 2010
Steve Simon

 

News and announcements

*Blog post
2010
Obsolete pages
This page is obsolete, but is being kept around anyway.
Aug 31, 2010
Steve Simon

 

Learning how to fit latent growth curve in Amos

*Blog post
2010
Being updated
Structural equations modeling
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Aug 25, 2010
Steve Simon

 

Is Evidence-Based Medicine too rigid

*Blog post
2010
Being updated
Evidence based medicine
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Aug 19, 2010
Steve Simon

 

What is a Generalized Estimating Equations Model

*Blog post
2010
Being updated
Mixed models
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Aug 19, 2010
Steve Simon

 

What is principal components analysis?

*Blog post
2010
Being updated
Data science
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Aug 19, 2010
Steve Simon

 

Competing books to the book I am planning to write

*Blog post
2010
Being updated
Professional details
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Aug 16, 2010
Steve Simon

 

What should clients get from you at the end of your first consulting session

*Blog post
2010
Being updated
Human side of statistics
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Aug 14, 2010
Steve Simon

 

Glossary for my second book

*Blog post
2010
Being updated
Professional details
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Aug 11, 2010
Steve Simon

 

What’s a fair price for SPSS?

*Blog post
2010
Being updated
SPSS software
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Aug 6, 2010
Steve Simon

 

Fighting the claim that any size difference is clinically important

*Blog post
2010
Being updated
Sample size justification
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Aug 5, 2010
Steve Simon

 

Standard operating procedures for a statistical consulting center

*Blog post
2010
Being updated
Human side of statistics
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Jul 30, 2010
Steve Simon

 

Acknowledgments for my second book

*Blog post
2010
Being updated
Professional details
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Jul 26, 2010
Steve Simon

 

When should research in a given area end?

*Blog post
2010
Systematic overviews
Someone asked a rather philosophical question, is there ever an end to research in a given area? Will there ever be a “last word” on a research topic. Here’s what I wrote in…
Jul 26, 2010
Steve Simon

 

Pooling different measures of risk in a meta-analysis

*Blog post
2010
Being updated
Systematic overviews
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Jul 26, 2010
Steve Simon

 

Sample chapter: The first three steps in selecting an appropriate sample size

*Blog post
2010
Being updated
Sample size justification
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Jul 24, 2010
Steve Simon

Sample chapter, the first three steps in selecting an appropriate sample size

*Blog post
2010
Sample size justification
As I mentioned in an earlier webpage, I am talking to some publishers about writing a second book. The working title is "Jumpstart Statistics: How to Restart Your Stalled…
Jul 24, 2010
Steve Simon

 

Tentative table of contents for my second book

*Blog post
2010
Being updated
Professional details
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Jul 24, 2010
Steve Simon

 

Jumpstart Statistics, a proposal for my second book

*Blog post
2010
Being updated
Professional details
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Jul 23, 2010
Steve Simon

 

Salary survey for Biostatisticians

*Blog post
2010
Being updated
Human side of statistics
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Jul 21, 2010
Steve Simon

 

Another counter-intuitive probability problem

*Blog post
2010
Being updated
Probability
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Jul 4, 2010
Steve Simon

 

Can political questions be resolved by science

*Blog post
2010
Being updated
Human side of statistics
Earlier versions are here and here.
Jul 1, 2010
Steve Simon

 

Resources using Stack Overflow

*Blog post
2010
Being updated
Teaching resources
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Jun 30, 2010
Steve Simon

 

Classic references in Statistics

*Blog post
2010
Being updated
Teaching resources
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Jun 29, 2010
Steve Simon

 

The SPSS t-test is confusing

*Blog post
2010
Being updated
SPSS software
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Jun 29, 2010
Steve Simon

 

What I use for talks instead of Powerpoint

*Blog post
2010
Being updated
Presenting research
Someone on LinkedIn asked a question about what technologies people use for their presentations (laptop, flipchart, or whiteboard). For most of my presentations, I use none…
Jun 28, 2010
Steve Simon

 

Fitting a new class of nonlinear regression models

*Blog post
2010
Being updated
Nonlinear regression
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Jun 28, 2010
Steve Simon

 

What I use for talks instead of Powerpoint

*Blog post
2010
Being updated
Presenting research
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Jun 28, 2010
Steve Simon

 

The futility of small sample sizes for evaluating a binary outcome

*Blog post
2010
Being updated
Small sample size issues
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Jun 16, 2010
Steve Simon

 

An example of a bad survey

*Blog post
2010
Being updated
Survey design
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Jun 11, 2010
Steve Simon

 

An interesting alternative to power calculattions

*Blog post
2010
Being updated
Sample size justification
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Jun 9, 2010
Steve Simon

 

Minimum sample size needed for a time series prediction

*Blog post
2010
Being updated
Time series
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Jun 8, 2010
Steve Simon

 

Computing power for an interaction in linear regression

*Blog post
2010
Being updated
Linear regression
Sample size justification
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Jun 3, 2010
Steve Simon

 

What is the premier conference for statistical consulting

*Blog post
2010
Being updated
Teaching resources
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May 28, 2010
Steve Simon

 

Lessons learned the hard way. Don’t presume to know how your software handles missing value codes

*Blog post
2010
Being updated
Missing data
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May 28, 2010
Steve Simon

 

Making simple modifications to a graph in SPSS

*Blog post
2010
Being updated
Graphical display
SPSS software
Earlier versions are here and here.
May 26, 2010
Steve Simon

 

How I got started in my career as an independent statistical consultant

*Blog post
2010
Being updated
Human side of statistics
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May 24, 2010
Steve Simon

 

How do I handle criticism

*Blog post
2010
Being updated
Human side of statistics
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May 21, 2010
Steve Simon

 

How to avoid charges of plagiarism

*Blog post
2010
Being updated
Writing research papers
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May 15, 2010
Steve Simon

 

Withdrawing from a study and taking your data with you

*Blog post
2010
Being updated
Ethics in research
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May 15, 2010
Steve Simon

 

Lessons learned the hard way: don’t throw good money after bad

*Blog post
2010
Being updated
Data management
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May 14, 2010
Steve Simon

 

More discussion on instrumental variables

*Blog post
2010
Being updated
Instrumental variables
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May 3, 2010
Steve Simon

 

What is a good surrogate measure for socioeconomic status

*Blog post
2010
Being updated
Evidence Based Medicine
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May 3, 2010
Steve Simon

 

Interpreting p-values in a published abstract, part 1

*Blog post
2010
Being updated
Hypothesis testing
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Apr 14, 2010
Steve Simon

 

Quiz about p-values

*Blog post
2010
Being updated
Hypothesis testing
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Apr 14, 2010
Steve Simon

 

Using entropy and the surprisal value to measure the degree of agreement with the consensus finding

*Blog post
2010
Information theory
One of the research problems that I am working on involves evaluation of a subjective rating system. I have been using information theory to try to identify objects where…
Apr 11, 2010
Steve Simon

 

What makes a good website?

*Blog post
2010
Being updated
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 7, 2010
Steve Simon

 

Should I learn R instead of SAS

*Blog post
2010
Being updated
R software
SAS software
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Apr 5, 2010
Steve Simon

 

Dealing with a large text file that crashes your computer

*Blog post
2010
Data science
Being updated
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Apr 2, 2010
Steve Simon

 

What to say when any data analysis is pointless

*Blog post
2010
Being updated
Human side of statistics
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Mar 25, 2010
Steve Simon

 

Calculating weights to correct for over and under sampling

*Blog post
2010
Sampling
Someone asked how to use weights to adjust for the fact that certain strata in a study were recruited more vigorously than other strata. For example, suppose you sampled at…
Mar 22, 2010
Steve Simon

 

Ordinal surprisals

*Blog post
2010
Being updated
Information theory
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Mar 20, 2010
Steve Simon

 

Can sex be an outcome variable?

*Blog post
2010
Being updated
Modeling issues
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Mar 16, 2010
Steve Simon

 

Ordinal entropy

*Blog post
2010
Being updated
Information theory
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Mar 11, 2010
Steve Simon

 

Finding duplicate records in a 19 million record database

*Blog post
2010
Being updated
Data science
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Mar 2, 2010
Steve Simon

 

Is intuition real?

*Blog post
2010
Critical appraisal
Someone asked if intuition is real.
Feb 25, 2010
Steve Simon

 

Abstract submitted to Missouri Regional Life Sciences Summit

*Blog post
2010
Being updated
Professional details
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Feb 13, 2010
Steve Simon

 

Exponential interpolation

*Blog post
2010
Being updated
Modeling issues
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Feb 11, 2010
Steve Simon

 

Fan page for The Monthly Mean

*Blog post
2010
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 11, 2010
Steve Simon

 

Meta-analysis for a single mean estimate

*Blog post
2010
Systematic overview
Someone noted that the usual meta analysis is carried out for the study on two treatment groups, usually for a difference in means. What if you had several studies…
Feb 11, 2010
Steve Simon

 

Statistical Literacy for Medical Librarians

*Blog post
2010
Being updated
Professional details
Earlier versions are here and here.
Feb 10, 2010
Steve Simon

 

Survey of librarians in the Midcontinental Chapter of the Medical Library Association

*Blog post
2010
Being updated
Professional details
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Feb 10, 2010
Steve Simon

 

Consulting remotely versus consulting in person

*Blog post
2010
Being updated
Human side of statistics
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Feb 8, 2010
Steve Simon

 

Humility is a good thing for researchers to have

*Blog post
2010
Being updated
Human side of statistics
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Feb 8, 2010
Steve Simon

 

What are the characteristics of a good consultant

*Blog post
2010
Being updated
Human side of statistics
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Feb 7, 2010
Steve Simon

 

Proposed poster for the Missouri Regional Life Sciences Summit

*Blog post
2010
Being updated
Professional details
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Feb 3, 2010
Steve Simon

 

Finding the standard deviation for a power calculation

*Blog post
2009
Being updated
Sample size justification
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Jan 27, 2010
Steve Simon

 

Facebook account

*Blog post
2010
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 25, 2010
Steve Simon

 

Abstracts for a possible upcoming talk

*Blog post
2010
Professional details
I might be asked to give a talk in February and I wanted to offer two possible choices. Here are the titles and abstracts of those talks.
Jan 20, 2010
Steve Simon

 

Masters or Phd in Statistics?

*Blog post
2010
Human side of statistics
Someone asked me about careers in Statistics and if you get the best career with a Masters degree or a PhD. That’s a very subjective choice and individual preferences should…
Jan 19, 2010
Steve Simon

 

SPSS or Stata?

*Blog post
2010
Being updated
SPSS software
Stata software
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Jan 19, 2010
Steve Simon

 

Where can I find free online textbooks

*Blog post
2010
Being updated
Teaching resources
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Jan 17, 2010
Steve Simon

 

The first three steps in selecting an appropriate sample size

*Blog post
2009
Being updated
Sample size justification
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Jan 15, 2010
Steve Simon

 

Lost page

*Blog post
2010
Being updated
Website details
Here is a series of recommended books, journal articles, and websites that I had collected during 2010. There is no particular topic and no special order.
Jan 14, 2010
Steve Simon

 

Power calculations for comparison of Poisson counts across two groups

*Blog post
2010
Being updated
Poisson regression
Sample size justification
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Jan 11, 2010
Steve Simon

 

What is residual confounding?

*Blog post
2010
Being updated
Linear regression
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Jan 6, 2010
Steve Simon

 

My life so far, fails to meet expectations

*Blog post
2010
Being updated
Human side of statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2010
Steve Simon

 

Entering and analyzing data from a two by two table

*Blog post
2009
Being updated
SPSS software
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Dec 14, 2009
Steve Simon

 

Randomly generating simple math problems using R

*Blog post
2009
Being updated
R software
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Nov 30, 2009
Steve Simon

 

Generating multinomial random variables in Excel

*Blog post
2009
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 23, 2009
Steve Simon

 

Jump start statistics for beginning researchers

*Blog post
2009
Being updated
Teaching resources
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Nov 7, 2009
Steve Simon

 

Rotating locations

*Blog post
2009
Being updated
Research design
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Nov 2, 2009
Steve Simon

 

Sneaking ineligible patients into a clinical trial

*Blog post
2009
Being updated
Fraud in research
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Oct 30, 2009
Steve Simon

 

What is a normal probability plot?

*Blog post
2009
Being updated
Probability distributions
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Oct 29, 2009
Steve Simon

 

Data layout for an ROC curve

*Blog post
2009
Being updated
Diagnostic testing
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Oct 16, 2009
Steve Simon

 

Accounting for clusters in an individually randomized clinical trial

*Blog post
2009
Randomization in research
I have a clinical trial with clusters (the clusters are medical practice), but unlike a cluster randomized trial, I am able to randomize within each cluster. From what I’ve…
Oct 13, 2009
Steve Simon

 

Use of Likert data with ANOVA

*Blog post
2009
Being updated
Analysis of variance
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Oct 13, 2009
Steve Simon

 

Are we statisticians gods?

*Blog post
2009
Being updated
Human side of statistics
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Oct 13, 2009
Steve Simon

 

Can I stop this study?

*Blog post
2009
Being updated
Early stopping
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Sep 16, 2009
Steve Simon

 

The problem with being too sensitive

*Blog post
2009
Being updated
Diagnostic testing
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Sep 16, 2009
Steve Simon

 

Simple longitudinal data analyses, part 1

*Blog post
2009
Being updated
Longitudinal data
Earlier versions are here and here.
Sep 15, 2009
Steve Simon

 

Getting a good cut-off

*Blog post
2009
Being updated
Diagnostic testing
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Sep 14, 2009
Steve Simon

 

Power for a three arm experiment

*Blog post
2009
Being updated
Sample size justification
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Sep 14, 2009
Steve Simon

 

The controversy over standardized beta coefficients

*Blog post
2009
Being updated
Linear regression
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Sep 12, 2009
Steve Simon

 

Tentative training schedule

*Blog post
2009
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 12, 2009
Steve Simon

 

Standard error for an odds ratio

*Blog post
2009
Being updated
Measuring benefit and risk
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Aug 12, 2009
Steve Simon

 

Formula for multiple imputation

*Blog post
2009
Being updated
Missing data
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 24, 2009
Steve Simon

 

Do multiple time points require a Bonferroni adjustment

*Blog post
2009
Being updated
Multiple comparisons
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Jul 8, 2009
Steve Simon

 

The perils of self-evaluation

*Blog post
2009
Being updated
Critical appraisal
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Jun 30, 2009
Steve Simon

 

Institute of Medicine report on conflict of interest

*Blog post
2009
Being updated
Conflict of interest
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May 24, 2009
Steve Simon

 

Data that IRBs should collect about themselves

*Blog post
2009
Being updated
Ethics in research
Earlier versions are here and here.
May 22, 2009
Steve Simon

 

The surprisal matrix and applications to exploration of very large discrete data sets

*Blog post
2009
Being updated
Information theory
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May 22, 2009
Steve Simon

 

NYTimes advice on increasing website traffic

*Blog post
2009
Being updated
Website details
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May 11, 2009
Steve Simon

 

Is this a case-control design?

*Blog post
2009
Being updated
Epidemiology
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Apr 28, 2009
Steve Simon

 

Can I use you as a teaching example?

*Blog post
2009
Being updated
Teaching resources
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 20, 2009
Steve Simon

 

Calculating NNT for

*Blog post
2009
Being updated
Measuring benefit and risk
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 20, 2009
Steve Simon

 

Calculating NNT for infection rates

*Blog post
2009
Being updated
Measuring benefit and risk
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Apr 15, 2009
Steve Simon

 

Two business contacts

*Blog post
2009
Being updated
Professional details
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Mar 30, 2009
Steve Simon

 

Short biography

*Blog post
2009
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 30, 2009
Steve Simon

 

I love to write

*Blog post
2009
Being updated
Professional details
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Mar 19, 2009
Steve Simon

 

Five points or seven points on a survey scale

*Blog post
2009
Being updated
Survey design
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Mar 12, 2009
Steve Simon

 

Good papers for a journal club

*Blog post
2009
Being updated
Teaching resources
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Mar 7, 2009
Steve Simon

 

Locating individual points on an ROC curve

*Blog post
2009
Being updated
Diagnostic testing
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Mar 5, 2009
Steve Simon

 

Sample size calculation for a logistic regression model

*Blog post
2009
Being updated
I might need to do a sample size justification for a logistic regression model. How would this be done? Let me outline some simple cases.
Feb 26, 2009
Steve Simon

 

Fewer than 10 events per variable

*Blog post
2009
Being updated
Small sample size issues
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 18, 2009
Steve Simon

 

Acknowledging the

*Blog post
2009
Writing research papers
A while back you assisted me with stats on my paper. I am finally ready to submit and wanted to know how I should appropriately acknowledge you for your participation since…
Feb 16, 2009
Steve Simon

 

Interpreting a negative autocorrelation

*Blog post
2009
Being updated
Time series
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 16, 2009
Steve Simon

 

Calibrating information

*Blog post
2009
Being updated
Information theory
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 28, 2009
Steve Simon

 

Updates for 2009

*Blog post
2009
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 21, 2009
Steve Simon

 

Changes in the adjusted hazard

*Blog post
2009
Being updated
Survival analysis
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Jan 19, 2009
Steve Simon

 

Drawing simple mathematical graphs

*Blog post
2009
Being updated
Graphical display
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 14, 2009
Steve Simon

 

A simple example of joint and conditional entropy

*Blog post
2009
Being updated
Information theory
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Jan 7, 2009
Steve Simon

 

Maybe Powerpoint isn’t so bad

*Blog post
2009
Being updated
Presenting research
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Jan 6, 2009
Steve Simon

 

Analyzing bad data

*Blog post
2009
Being updated
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Jan 1, 2009
Steve Simon

 

DNA binding image

*Blog post
2009
Being updated
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Jan 1, 2009
Steve Simon

 

New Bioinformatics degree

*Blog post
2009
Being updated
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Jan 1, 2009
Steve Simon

 

A sportswriter tackles the Monty Hall problem

*Blog post
2009
Being updated
Probability
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Jan 1, 2009
Steve Simon

 

What is the effect of an unmeasured covariate?

*Blog post
2009
Being updated
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Jan 1, 2009
Steve Simon

 

Developing a website logo

*Blog post
2009
Being updated
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Jan 1, 2009
Steve Simon

 

A false sense of frugality

*Blog post
2008
Being updated
Data management
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Dec 17, 2008
Steve Simon

 

Viewing SPSS and SAS output without buying SPSS and SAS

*Blog post
2008
Being updated
SAS software
SPSS software
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Dec 17, 2008
Steve Simon

 

Using a sub-optimal approach in meta-analysis

*Blog post
2008
Being updated
Systematic overviews
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Dec 16, 2008
Steve Simon

 

Zotero, The Next Generation Research Tool

*Recommendation
2008
Being updated
Writing research papers
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Dec 1, 2008
Steve Simon

 

What is the Lan-DeMets approach to interim analysis

*Blog post
2008
Being updated
Early stopping in clinical trials
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Nov 21, 2008
Steve Simon

 

Updates for 2008

*Blog post
2008
Being updated
Obsolete page
Professional details
This page is osolete. I am keeping it around for mostly nostalgic reasons.
Nov 17, 2008
Steve Simon

 

The Myth of Equipoise in Phase 1 Clinical Trials

*Recommendation
2008
Being updated
Systematic overviews
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Nov 5, 2008
Steve Simon

 

The statistician who supposes that…

*Quotation
2008
Being updated
Ethics in research
Interesting quote: The statistician who supposes that his main contribution to the planning of an experiment will involve statistical theory, finds repeatedly that he makes…
Nov 5, 2008
Steve Simon

 

Explaining CART models in simple terms

*Blog post
2008
Being updated
Data mining
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Nov 5, 2008
Steve Simon

 

Four assumptions of multiple regression that researchers should always test

*Recommendation
2008
Being updated
Linear regression
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Nov 5, 2008
Steve Simon

 

The Myth of Equipoise in Phase 1 Clinical Trials

*Recommendation
2008
Being updated
Ethics in research
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Nov 5, 2008
Steve Simon

 

Reading abstracts instead of the full paper

*Blog post
2008
Being updated
Critical appraisal
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Nov 5, 2008
Steve Simon

 

Statisticians are not gatekeepers

*Blog post
2008
Being updated
Human side of statistics
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Nov 4, 2008
Steve Simon

 

Helping Doctors and Patients Make Sense of Health Statistics

*Recommendation
2008
Being updated
Teaching resources
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Nov 1, 2008
Steve Simon

 

Comparing a set of microarray experiments to a model experiment

*Blog post
2008
Being updated
Data science
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Nov 1, 2008
Steve Simon

 

Components of placebo effect, Randomised controlled trial in patients with irritable bowel syndrome

*Recommendation
2008
Being updated
Placebos in research
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Nov 1, 2008
Steve Simon

 

Regression with SAS. Additional coding systems for categorical variables

*Recommendation
2008
Being updated
Analysis of variance
SAS software
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Nov 1, 2008
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Survey design
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Oct 28, 2008
Steve Simon

 

Refusing to analyze a data set

*Blog post
2008
Being updated
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Oct 28, 2008
Steve Simon

 

A standard deviation that is too big for its own britches

*Blog post
2008
Being updated
Descriptive statistics
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Oct 22, 2008
Steve Simon

 

Computing a difference between first and last variables

*Blog post
2008
Data management
SPSS software
Being updated
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Oct 20, 2008
Steve Simon

 

Intervening variable

*Recommendation
2008
Being updated
Hypothesis testing
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Oct 20, 2008
Steve Simon

 

Variables and hypotheses

*Recommendation
2008
Being updated
Hypothesis testing
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Oct 20, 2008
Steve Simon

 

Example of power calculation for a repeated measures design

*Blog post
2008
Being updated
Sample size justification
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Oct 19, 2008
Steve Simon

 

Errors in statistical methodology

*Blog post
2008
Being updated
Critical appraisal
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Oct 19, 2008
Steve Simon

 

Biostatistics or Health Informatics programs in or near Kansas City

*Blog post
2008
Being updated
Teaching resources
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Oct 18, 2008
Steve Simon

 

Defending Bonferroni

*Blog post
2008
Being updated
Multiple comparisons
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Oct 18, 2008
Steve Simon

 

Interpretations for a two by two table

*Blog post
2008
Being updated
Probability concepts
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Oct 18, 2008
Steve Simon

 

Normality assumptions for the paired t-test

*Blog post
2008
Being updated
Hypothesis testing
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Oct 14, 2008
Steve Simon

 

T-test with 3 treatment values and 2 controls

*Blog post
2008
Being updated
Small sample size issues
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Oct 14, 2008
Steve Simon

 

Example of power calculation for a repeated measures design

*Blog post
2008
Being updated
Sample size justification
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Oct 11, 2008
Steve Simon

 

A simple example of overfitting

*Blog post
2008
Being updated
Modeling issues
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Oct 8, 2008
Steve Simon

 

How do I fit a piecewise linear regression

*Blog post
2008
Being updated
Linear regression
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Oct 7, 2008
Steve Simon

 

What’s new in SPSS 17

*Blog post
2008
Being updated
SPSS software
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Oct 7, 2008
Steve Simon

 

Evaluating private conflicts of interest

*Blog post
2008
Being updated
Conflict of interest
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Oct 1, 2008
Steve Simon

 

Can I ask you a question

*Blog post
2008
Being updated
Website details
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Sep 25, 2008
Steve Simon

 

Comparing pre and post data with a parallel control group

*Blog post
2008
Being updated
Mixed models
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Sep 25, 2008
Steve Simon

 

Processing skip fields in SPSS

*Blog post
2008
Being updated
SPSS software
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Sep 25, 2008
Steve Simon

 

Venn diagrams with proportional areas

*Blog post
2008
Being updated
Graphical display
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Sep 23, 2008
Steve Simon

 

Links and references that I need to add

*Blog post
2008
Being updated
Website details
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Sep 18, 2008
Steve Simon

 

Can an outcome with three levels be used in logistic regression

*Blog post
2008
Being updated
Logistic regression
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Sep 18, 2008
Steve Simon

 

Categorizing entropy values

*Blog post
2008
Being updated
Information theory
Being updated
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Sep 17, 2008
Steve Simon

 

Jackknife applied to entropy calculations

*Blog post
2008
Being updated
Information theory
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Sep 15, 2008
Steve Simon

 

Use of entropy measures for sperm morphology classification

*Blog post
2008
Being updated
Information theory
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Sep 13, 2008
Steve Simon

 

How do you compute a continuity correction for a confidence interval

*Blog post
2008
Confidence intervals
Being updated
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Sep 12, 2008
Steve Simon

 

Comparisons involving distinct groups collected at different times and with different methods

*Blog post
2008
Being updated
Observational studies
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Sep 12, 2008
Steve Simon

 

What does “population-based” mean?

*Blog post
2008
Being updated
Writing research papers
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Sep 12, 2008
Steve Simon

 

Where did you get that formula for the confidence interval

*Blog post
2008
Confidence intervals
Being updated
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Sep 9, 2008
Steve Simon

 

Multiple email accounts

*Blog post
2008
Being updated
Professional details
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Sep 9, 2008
Steve Simon

 

The case of Ranjit Kumar Chandra

*Blog post
2008
Ethics in research
Being updated
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Sep 8, 2008
Steve Simon

 

Applying the sequence logo concept to data quality

*Blog post
2008
Being updated
Data quality
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Sep 4, 2008
Steve Simon

 

Checks for data quality using metadata

*Blog post
2008
Data management
Being updated
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Aug 28, 2008
Steve Simon

 

Controversies with a test for ovarian cancer

*Blog post
2008
Being updated
Ethics in research
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Aug 27, 2008
Steve Simon

 

Entropy as a measure of data quality across multiple variables

*Blog post
2008
Being updated
Information theory
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Aug 25, 2008
Steve Simon

 

Where to look for information in a controversial area

*Blog post
2008
Critical appraisal
Being updated
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Aug 20, 2008
Steve Simon

 

What resources are available for fellows

*Blog post
2008
Being updated
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Aug 20, 2008
Steve Simon

Source for sample size formula

*Blog post
2008
Being updated
Sample size justification
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 20, 2008
Steve Simon

 

Is there a scientific basis for EBM?

*Blog post
2008
Being updated
Evidence based medicine
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Aug 20, 2008
Steve Simon

 

Another inquiry about slash and burn models

*Blog post
2008
Being updated
Logistic regression
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Aug 20, 2008
Steve Simon

 

Social networking as a business tool

*Blog post
2008
Being updated
Human side of statistics
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Aug 19, 2008
Steve Simon

 

Cumulative entropy as a measure of data quality

*Blog post
2008
Being updated
Information theory
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Aug 11, 2008
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Multiple comparisons
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Aug 9, 2008
Steve Simon

 

Anti-intellectualism

*Quotation
2008
Being updated
Critical appraisal
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Aug 8, 2008
Steve Simon

 

Interval scale for count data

*Blog post
2008
Being updated
Descriptive statistics
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Aug 7, 2008
Steve Simon

 

Harsh sanctions are only part of the solution

*Blog post
2008
Being updated
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Aug 6, 2008
Steve Simon

 

Reporting of adverse events

*Blog post
2008
Adverse events
Being updated
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Aug 5, 2008
Steve Simon

 

Comparing two proportions out of the same multinomial population

*Blog post
2008
Being updated
Multinomial probabilities
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Aug 5, 2008
Steve Simon

 

Resources from the Statistical Consulting Section of the American Statistical Association

*Blog post
2008
Human side of statistics
Being updated
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Aug 2, 2008
Steve Simon

 

Naming conventions for variables

*Blog post
2008
Being updated
Data management
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Jul 30, 2008
Steve Simon

 

Business aspects of an independent statistical consultant

*Blog post
2008
Being updated
Human side of statistics
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Jul 28, 2008
Steve Simon

 

What does the FDA think about Bayesian statistics

*Blog post
2008
Being updated
Bayesian statistics
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Jul 28, 2008
Steve Simon

 

Should I abandon FrontPage?

*Blog post
2008
Obsolete pages
Website details
This page is obsolete, but I am keeping it around for sentimental reasons. Note: 2025-07-19. I did try KompoZer and it was okay, but ended up using other software. I am not…
Jul 24, 2008
Steve Simon

 

Plug for accrual research

*Blog post
2008
Accrual problems
Being updated
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Jul 24, 2008
Steve Simon

 

My very first meta-analysis

*Blog post
2008
Being updated
Systematic overviews
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Jul 23, 2008
Steve Simon

 

Godwin’s Law

*Blog post
2008
Accrual problems
Being updated
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Jul 23, 2008
Steve Simon

 

Mail and calendar software I use in my new job

*Blog post
2008
Being updated
Professional details
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Jul 23, 2008
Steve Simon

 

What distribution does this data come from

*Blog post
2008
Being updated
Modeling issues
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Jul 23, 2008
Steve Simon

 

Survey results from nine out of thirty six

*Blog post
2008
Being updated
Small sample size issues
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Jul 21, 2008
Steve Simon

 

Where can I learn more about Statistics?

*Blog post
2008
Being updated
Teaching resources
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Jul 18, 2008
Steve Simon

 

Software for bootstrap and resampling

*Blog post
2008
Being updated
Resampling methods
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Jul 18, 2008
Steve Simon

 

Can I use some material from your website

*Blog post
2008
Being updated
Website details
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Jul 18, 2008
Steve Simon

 

Getting on and off various email lists

*Blog post
2008
Being updated
Teaching resources
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Jul 17, 2008
Steve Simon

 

Hire me as a consultant

*Blog post
2008
Being updated
Professional details
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Jul 15, 2008
Steve Simon

 

A misleading bar graph

*Blog post
2008
Being updated
Graphical display
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Jul 15, 2008
Steve Simon

 

Undeclared missing code leads

*Blog post
2008
Being updated
Missing data
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Jul 15, 2008
Steve Simon

 

Using Google to search through my website

*Blog post
2008
Being updated
Website details
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Jul 15, 2008
Steve Simon

 

How to report a one-tailed Fisher’s Exact Test

*Blog post
2008
Being updated
Hypothesis testing
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Jul 12, 2008
Steve Simon

 

Pearson correlation and ordinal data

*Blog post
2008
Being updated
Linear regression
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Jul 11, 2008
Steve Simon

 

Pearson correlation and ordinal data don’t mix

*Blog post
2008
Being updated
Linear regression
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Jul 11, 2008
Steve Simon

 

Where did that standard deviation come from

*Blog post
2008
Being updated
Sample size justification
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Jul 9, 2008
Steve Simon

 

Distrust of a Bayesian

*Blog post
2008
Bayesian statistics
Being updated
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Jul 1, 2008
Steve Simon

 

How many files

*Blog post
2008
Being updated
Website details
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Jun 24, 2008
Steve Simon

 

Bootstrap estimates of the standard error

*Blog post
2008
Unusual data
A regular correspondent (JU) on the MEDSTATS email discussion group asked about using the bootstrap to estimate the standard error of the mean in a simple case with 9 data…
Jun 20, 2008
Steve Simon

 

Can I run a quantitative analysis on this data?

*Blog post
2008
Being updated
Small sample size issues
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Jun 17, 2008
Steve Simon

 

Running R on a web server

*Blog post
2008
Being updated
R software
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jun 17, 2008
Steve Simon

 

Modeling a declining count variable

*Blog post
2008
Poisson regression
Rmarkdown code
I’ve been working on an interesting project that requires Poisson regression. A company sends out a mailing and gets a certain number of telephone calls back on each of the…
Jun 14, 2008
Steve Simon

 

Criticism of random effects in a meta-analysis

*Blog post
2008
Being updated
Systematic overviews
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Jun 14, 2008
Steve Simon

 

Eliciting a prior distribution for rejection/refusal rates

*Blog post
2008
Accrual problems
Being updated
I got a question about the Bayesian model for rejection/refusal rates. I had used three prior distributions in my calculations, a Beta(10,40), a Beta(45,5), and a…
Jun 7, 2008
Steve Simon

 

When does heterogeneity become a concern?

*Blog post
2008
Being updated
Analysis of variance
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Jun 5, 2008
Steve Simon

 

Why it’s impossible to keep a resume current

*Blog post
2008
Being updated
Professional details
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Jun 5, 2008
Steve Simon

 

How wide can you make a line of your web page?

*Blog post
2008
Being updated
Website details
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May 27, 2008
Steve Simon

 

A simple Bayesian model for

*Blog post
2008
Accrual problems
Being updated
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May 26, 2008
Steve Simon

 

A short biography that can be used as an introduction

*Blog post
2008
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 9, 2008
Steve Simon

 

Why does a Bayesian approach make sense for monitoring accrual?

*Blog post
2008
Being updated
Bayesian statistics
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May 8, 2008
Steve Simon

 

Slipped deadlines and sample size shortfalls in a random sample of research studies

*Blog post
2008
Accrual problems
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 7, 2008
Steve Simon

 

Monitoring refusals and exclusions in a clinical trial

*Blog post
2008
Being updated
Accrual problems
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May 1, 2008
Steve Simon

 

Directions to my new office

*Blog post
2008
Obsolete page
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Apr 25, 2008
Steve Simon

 

Nomination for the Kreamer Award for Research Excellence

*Blog post
2008
Being updated
Professional details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Apr 24, 2008
Steve Simon

 

Upcoming topics in Poisson regression

*Blog post
2008
Obsolete page
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Apr 24, 2008
Steve Simon

 

Evidence Based Medicine for patients

*Blog post
2008
Being updated
Information searching
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Apr 23, 2008
Steve Simon

 

A brief overview of instrumental variables

*Blog post
2008
Being updated
Unusual data
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Apr 14, 2008
Steve Simon

 

A simple math error

*Blog post
2008
Being updated
Website details
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Apr 6, 2008
Steve Simon

 

What does one-third of the way through a study mean?

*Blog post
2008
Being updated
Early stopping
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Apr 6, 2008
Steve Simon

 

Calculating statistics on whole numbers

*Blog post
2008
Being updated
Descriptive statistics
Writing research papers
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Apr 4, 2008
Steve Simon

 

An alternative to the p-value

*Blog post
2008
Being updated
Hypothesis testing
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Apr 3, 2008
Steve Simon

 

Why we need case studies of research ethics in graphic novel format

*Blog post
2008
Ethics in research
I was asked to provide some justification for a project I am working on, case studies in research ethics using a graphic novel format. Here is what I wrote.
Apr 3, 2008
Steve Simon

 

What sort of statistical training is needed for basic scientists?

*Blog post
2008
Being updated
Teaching resources
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Mar 29, 2008
Steve Simon

 

Statistics for Boards

*Blog post
2008
Being updated
Teaching resources
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Mar 25, 2008
Steve Simon

 

When a client asks for a bad analysis

*Blog post
2008
Being updated
Human side of statistics
Multiple comparisons
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Mar 24, 2008
Steve Simon

 

Presenting unadjusted and adjusted estimates side by side

*Blog post
2008
Being updated
Modeling issues
Writing research papers
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 24, 2008
Steve Simon

 

ROC curve for an imperfect gold standard

*Blog post
2008
Being updated
Diagnostic testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 12, 2008
Steve Simon

 

Moving content to a private site

*Blog post
2008
Being updated
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 12, 2008
Steve Simon

 

ROC curve for an imperfect gold standard

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 12, 2008
Steve Simon

 

Simplifying repeated measurements

*Blog post
2008
Being updated
Multilevel models
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 12, 2008
Steve Simon

 

Losing web pages in the mass of information

*Blog post
2008
Being updated
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 5, 2008
Steve Simon

 

Calculating NNT for observational studies

*Blog post
2008
Being updated
Measuring benefit and risk
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 3, 2008
Steve Simon

 

Assessing the assumption of an exponential distribution

*Blog post
2008
Being updated
Modeling issues
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 25, 2008
Steve Simon

 

What is a critical value?

*Blog post
2008
Being updated
Hypothesis testing
Someone wrote in asking about the difference between a p-value and a critical value. I define a p-value on my web pages already. The critical value is typically a percentile…
Feb 22, 2008
Steve Simon

 

Multiple methods for computing percentiles

*Blog post
2008
Descriptive statistics
A recent discussion on the Medstats group highlighted some of the confusion about computing percentiles. I use a simple formula. If you want the pth percentile of a set of n…
Feb 13, 2008
Steve Simon

 

Does prevalence affect sensitivity

*Blog post
2008
Being updated
Diagnostic testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 31, 2008
Steve Simon

 

A simple example of a Kaplan-Meier curve

*Blog post
2008
Being updated
Survival analysis
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 24, 2008
Steve Simon

 

How do you analyze safety data

*Blog post
2008
Adverse events
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 22, 2008
Steve Simon

 

Finding only the important studies

*Blog post
2008
Being updated
Systematic overviews
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 21, 2008
Steve Simon

 

What have you changed your mind about

*Blog post
2008
Being updated
Teaching resources
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 18, 2008
Steve Simon

 

Too much power and precision?

*Blog post
2008
Sample size justification
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 9, 2008
Steve Simon

 

The post-modern assault on evidence-based medicine, part 3

*Blog post
2008
Being updated
Critical appraisal
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 7, 2008
Steve Simon

 

High altitude effects on athletic performance

*Blog post
2008
Being updated
Poisson regression
Teaching resources
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 5, 2008
Steve Simon

 

What statistic should I use when?

*Blog post
2008
Being updated
Analysis of variance
Linear regression
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 4, 2008
Steve Simon

 

Type III error

*Blog post
2008
Being updated
Hypothesis testing
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 3, 2008
Steve Simon

 

I hate bad research examples

*Blog post
2008
Being updated
Teaching resources
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

Cytel software has developed a Poisson

*Blog post
2008
Being updated
Accrual problems
This page is missing, both in the current version in my blog and in earlier versions. I should delete these pages totally and pretend that they never existed.
Jan 1, 2008
Steve Simon

 

New format for articles, books, and websites

*Blog post
2008
Being updated
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

New personal pages

*Blog post
2008
Being updated
Personal details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

To be updated

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

Reliable diagnosis of cataracts

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

To be updated

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

To be updated

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

Resources for Statistical Evidence in Medical Trials

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

Reviews of “Statistical Evidence.”

*Blog post
2008
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

The glitter of…

*Quotation
2008
Critical appraisal
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2008
Steve Simon

 

When should you use a log transformation?

*Blog post
2007
Linear regression
How do I know whether it is appropriate to use a log transformation for my data?
Dec 28, 2007
Steve Simon

 

Who wrote the law that mandates PowerPoint?

*Blog post
2007
Presenting research
A recent filler item in BMJ, The PowerPoint presentation, written by David Isaacs, Stephen Isaacs, and Dominic Fitzgerald, provided a light hearted view of the bad habits…
Dec 28, 2007
Steve Simon

 

Analyzing data under an Intention to Treat model

*Blog post
2007
Randomization in research
I need to know how to analyze a data set using the intention to treat principle.
Dec 19, 2007
Steve Simon

 

The post-modern assault on evidence-based medicine

*Blog post
2007
Critical appraisal
I never got around to submitting an article to Skeptic Magazine, but here is an update of something I wrote back in 2007 about post-modern philosophy and evidence based…
Dec 18, 2007
Steve Simon

 

A Poisson regression model with interactions

*Blog post
2007
Poisson regression
I got a question about how to interpret an interaction term in a Poisson regression model. The first thing to remember is that the estimates in a Poisson regression model…
Dec 12, 2007
Steve Simon

 

No longer the sole statistician?

*Blog post
2007
Professional details
Children’s Mercy Hospital is hiring a second statistician. Hooray! It’s a great place to work and I’m hoping we can hire someone quickly. The links to describe the position…
Nov 28, 2007
Steve Simon

 

Testing for an increasing trend in a proportion

*Blog post
2007
Logistic regression
Someone asked me how to see if a sequence of four proportions is showing a significant increase over time. The data represents the proportion of imaging studies that are…
Nov 26, 2007
Steve Simon

 

Tracking adverse events during kidney biopsy

*Blog post
2007
Adverse events
This is a major revision of the March 14, 2007 and April 5, 2007 weblog entries. I have been helping a colleague who is interested in monitoring the safety of kidney biopsy…
Nov 19, 2007
Steve Simon

 

What, exactly, is a child?

*Blog post
2007
Children in research
I’m updating a talk on research issues associated with pediatric treatments. Before I start throwing around terms like “paediatric” and “child,” I should take some time to…
Nov 19, 2007
Steve Simon

 

Tracking central line infections over time

*Blog post
2007
Adverse events
I’m working with a group that is tracking central line infections over time. There were 22 infections over the previous year, and the infants were divided into five risk…
Nov 18, 2007
Steve Simon

 

My page names are too long

*Blog post
2007
Website details
About three years ago, I started using longer names for my webpages. It makes it easier for me to maintain and upgrade these pages. So instead of a short name like…
Nov 17, 2007
Steve Simon

 

Monitoring adverse events during peritoneal dialysis

*Blog post
2007
Adverse events
One of the doctors I was working with had an interesting data set examining adverse events in patients with peritoneal dialysis. These patients start treatment with…
Nov 15, 2007
Steve Simon

 

Stair step interpolation in R

*Blog post
2007
Graphical display
R software
I am working on some charts that show discrete (sudden) jumps at specific time points. This requires the use of stair step interpolation, because if you just connected the…
Nov 15, 2007
Steve Simon

 

NNH talk update

*Blog post
2007
Adverse events
Last year, I gave a talk for PharmaIQ about continuous monitoring of the number needed to harm. I want to update this talk for a second audience in December. Here’s the…
Nov 12, 2007
Steve Simon

 

Reforming conflict of interest statements

*Blog post
2007
Conflict of interest
In a recent talk, I was asked to disclose any conflicts of interest. I did so, but I also commented that the organization I was speaking to, as well as most other…
Nov 12, 2007
Steve Simon

 

Postlude to my Dallas talk

*Blog post
2007
Diagnostic testing
I gave a talk this morning to the American College of Allergy, Asthma & Immunology (ACAAI). I documented my preparations for this talk on my webpages and wanted to share…
Nov 11, 2007
Steve Simon

 

Grow up and learn how to do Statistics

*Blog post
2007
Human side of statistics
I attended a talk by Dr. Martha Curley about parental presence during invasive procedures and resuscitation. Early in the talk, Dr. Curley mentioned a bell shaped curve and…
Nov 8, 2007
Steve Simon

 

Handout for diagnostic testing

*Blog post
2007
Diagnostic testing
I have been busy preparing a handout describing the basics of diagnostic testing (e.g., sensitivity and specificity), the medical issues associated with these tests (e.g.…
Nov 6, 2007
Steve Simon

 

New categories needed

*Blog post
2007
Broken link
Website details
I need to develop some new categories. The first will discuss report cards, league tables, and other measures of hospital and individual performance. The pages I have on…
Oct 18, 2007
Steve Simon

 

Open-access (OA) journals and their impact on research and the practice of medicine (created October 18, 2007

*Blog post
2007
Broken link
Writing research papers
This talk will cover the following topics:
Oct 18, 2007
Steve Simon

 

Revising my definition section

*Blog post
2007
Website details
I have a section on definitions and it is an odd mix of things. I want to simplify these pages by separating examples of how to calculate a particular statistic from the…
Oct 18, 2007
Steve Simon

 

Unused resources for my open access talk

*Blog post
2007
Broken link
Writing research papers
I am giving a talk on Open Access journals at the Grand Rounds for CMH on Thursday, October 17. See my web summary and my pdf slides. Here are some resources which (in the…
Oct 14, 2007
Steve Simon

 

Illustrations for a case study of the TGN 1412 trial (created 2007-10-12).

*Blog post
2007
Ethics in research
I am working with a graphic artist to produce some illustrations to help explain what happened during the disastrous TGN1412 trial. The general structure of these…
Oct 12, 2007
Steve Simon

 

Confidence interval for a rate

*Blog post
2007
Confidence intervals
Poisson regression
How do you calculate a confidence interval for a rate?
Oct 10, 2007
Steve Simon

 

Case study of accrual in a clinical trial, part 2

*Blog post
2007
Accrual problems
I received additional accrual data on a clinical trial I am monitoring. To review, the trial started on August 28, 2007 and will continue until January 31, 2008, for a total…
Oct 9, 2007
Steve Simon

 

Seminar on Open Access Journals

*Blog post
2007
Writing research papers
I was inspired by a talk by Jim Pitman, President of the IMS, at the Joint Statistical Meetings in August, “Open Access to Professional Information” so when an opportunity…
Oct 5, 2007
Steve Simon

 

Educational and networking opportunities for statisticians in the Kansas City area

*Blog post
2007
Teaching resources
There are three groups that offer seminars, training classes and informal networking opportunities for statisticians in the Kansas City area.
Oct 4, 2007
Steve Simon

 

An alternate way of viewing accrual

*Blog post
2007
Accrual problems
I was talking about a project with a fellow in Emergency Medicine and during the discussion realized a different way of looking at accrual in a clinical trial. She plans to…
Oct 3, 2007
Steve Simon

 

Help for Statistics at UMKC and KUMC

*Blog post
2007
Obsolete page
Professional details
Note: a large number of people listed here have moved on.
Oct 1, 2007
Steve Simon

 

Alphabetical bookmark list

*Blog post
2007
Obsolete page
Website details
This page is obsolete. I am keeping it around for nostalgic reasons.
Sep 27, 2007
Steve Simon

 

Html debris copied from other websites

*Blog post
2007
Obsolete page
Website details
[Note: These stray tags are no longer an issue since I converted to using blogdown to create webpages.]
Sep 27, 2007
Steve Simon

 

The latest word on my promotion

*Blog post
2007
Professional details
In previous weblog entries,
Sep 27, 2007
Steve Simon

 

Patterns to look for in a histogram

*Blog post
2007
Graphical display
When you plot your data in a histogram (or a stem and leaf diagram), you should look for patterns. Here are examples of three of the most important ones.
Sep 21, 2007
Steve Simon

 

The order of entering interactions into a model

*Blog post
2007
Logistic regression
I like your titanic example! But shouldn’t you enter the interaction term on a second step following entry of the main effects on the first step? If you enter the terms all…
Sep 20, 2007
Steve Simon

 

What does a statistician do all day?

*Blog post
2007
Human side of statistics
I have to write up a job description for a statistician. This includes essential functions and important functions. Here are two examples. The first is how my own job was…
Sep 17, 2007
Steve Simon

 

How many webpages have I written?

*Blog post
2007
Administrative details
Obsolete page
[Note: this page shows counts from the year 2007. The website has grown substantially since then.]
Sep 14, 2007
Steve Simon

 

Case study of accrual in a clinical trial

*Blog post
2007
Accrual problems
Someone came by today with a project where he wants to monitor the accrual in a clinical trial. The trial started on August 28, 2007 and will continue until January 31…
Sep 11, 2007
Steve Simon

 

Is my confidence interval wide?

*Blog post
2007
Confidence intervals
Dear Professor Mean, I have a case-control design. Among the cases, 271 were exposed and 317 were unexposed. Among the controls, 125 were exposed and 976 were unexposed.…
Sep 11, 2007
Steve Simon

 

My promotion application

*Blog post
2007
Professional details
In previous weblog entries (see below), I discussed the process for applying for a promotion to Full Professor. Yesterday, I turned in a completed a promotion application. I…
Sep 5, 2007
Steve Simon

 

Resources for grant writers

*Blog post
2007
Broken link
Grant writing
If you are interested in writing a grant, there are a lot of free resources that you can consult. Many of these are written by the same people who hand out the grant money…
Sep 4, 2007
Steve Simon

 

Extra information for the resume of Stephen D. Simon

*Blog post
2007
Obsolete page
Professional details
Notice to headhunters: I am not looking for a job. I am posting this resume to help with my collaborative efforts with others outside Children’s Mercy Hospital.
Sep 4, 2007
Steve Simon

 

External scholars needed to review my promotion materials

*Blog post
2007
Professional details
Although I do all my work at Children’s mercy Hospital, I have a joint appointment as Associate Professor in the School of Medicine at the University of Missouri-Kansas…
Aug 31, 2007
Steve Simon

 

Are we assuming a normal sample or a normal population?

*Blog post
2007
Modeling issues
I’m fitting an ANOVA model to a sample of 25 observations, and the data is quite skewed. I’m quite worried about this, but my husband reassures me that this is not a…
Aug 30, 2007
Steve Simon

 

What makes pediatric research different?

*Blog post
2007
Children in research
I may be asked to give a repeat performance of Stats #53: Signal Detection Strategies for Paediatric Treatments. This is a three hour class that I gave last year in London.…
Aug 29, 2007
Steve Simon

 

Analyzing data from a simple crossover design

*Blog post
2007
Analysis of variance
A doctor brought me some data from a crossover design and asked me to help analyze it. The analysis was a bit trickier than I had expected, so I reviewed some of the…
Aug 22, 2007
Steve Simon

 

Common sources of confusion in a class on quality control

*Blog post
2007
Control charts
I presented a training class, Stats #18: Quality Control: A Hands-On Workshop, for the American Society for Andrology. The major emphasis was on the computation of control…
Aug 22, 2007
Steve Simon

 

Accrual grant, Round 3

*Blog post
2007
Accrual problems
Last year, I applied for a Kansas City Area Life Sciences Institute (KCALSI) Research Development grant. It was not funded, but a subsequent grant that I submitted to the…
Aug 21, 2007
Steve Simon

 

How good is my prediction?

*Blog post
2007
Modeling issues
I have two time series of data, one actual and one predicted. Since I’m quite new to statistical methods, I would like to know what methods are used to evaluate the…
Aug 13, 2007
Steve Simon

 

Does promoting your book constitute a conflict of interest?

*Blog post
2007
Conflict of interest
I give lots of talks and I usually put in a plug for my book, Statistical Evidence in Medical Trials. I even promote my book in the signature file that I put at the bottom…
Aug 13, 2007
Steve Simon

 

Need for a conflict of interest policy

*Blog post
2007
Conflict of interest
I attended a very interesting session at the Joint Statistical Meetings last week on conflict of interest. I asked a question during the session that seemed quite obvious to…
Aug 9, 2007
Steve Simon

 

Justifying the sample size for a microarray study

*Blog post
2007
Data mining
Sample size justification
I’m helping out with a grant proposal that is using microarrays for part of the analysis. A microarray is system for quantitative measurement of circulating mRNA in human…
Aug 9, 2007
Steve Simon

 

Which expert should you believe?

*Blog post
2007
Critical appraisal
There’s a common saying in research circles that goes something like this: “For every PhD, there is an equal and opposite PhD.” That saying is certainly true in my…
Aug 3, 2007
Steve Simon

 

Bibliography of papers relating to predicting accrual in clinical trials

*Blog post
2007
Accrual problems
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 28, 2007
Steve Simon

 

Should I use the heteroscedastic t-test?

*Blog post
2007
Hypothesis testing
I am using Excel to do a t-test to see if there is a difference between blood glucose levels in babies who received 2 different treatments. I want to know if the new…
Jul 26, 2007
Steve Simon

 

Conflict of interest in the Wakefield MMR study

*Blog post
2007
Children in research
Conflict of interest
Ethics in research
An interesting case study in conflict of interest (perhaps a bit too complex to be described fairly in this brief weblog entry) involves a controversial paper. The lead…
Jul 26, 2007
Steve Simon

 

Continuing education questions for a talk on diagnostic tests

*Blog post
2007
Diagnostic testing
As part of my talk to the American College of Allergy, Asthma & Immunology, I have been asked to present two questions related to my topic (Use of Diagnostic Tests for…
Jul 24, 2007
Steve Simon

 

Classic calculations for a diagnostic test

*Blog post
2007
Diagnostic testing
I created a table that illustrates many of the classic calculations for a diagnostic test.
Jul 20, 2007
Steve Simon

 

Conflict of interest list

*Blog post
2007
Conflict of interest
Professional details
I was asked to fill out a conflict of interest form for a talk I will be giving in December. While I have not gotten any money directly from drug companies recently, I do…
Jul 18, 2007
Steve Simon

 

I don’t want to use a randomized trial

*Blog post
2007
Observational studies
Randomization
An email on the MedStats group outlines a new treatment that is:
Jul 18, 2007
Steve Simon

 

Code for drawing new likelihood ratio slide rule

*Blog post
2007
Diagnostic testing
I have made some minor changes to my likelihood ratio slide. The original code was lost somewhere, so I wrote some new code and added documentation. I also changed the…
Jul 12, 2007
Steve Simon

 

Code for drawing new likelihood ratio slide rule

*Blog post
2007
Diagnostic testing
Rmarkdown code
I have made some minor changes to my likelihood ratio slide. The original code was lost somewhere, so I wrote some new code and added documentation. I also changed the…
Jul 12, 2007
Steve Simon

 

The research world is not black and white

*Blog post
2007
Critical appraisal
I was asked to review a commentary about studies involving remote healing (which includes prayer studies as a subgroup). It is not available yet on the web, but I’ll try to…
Jul 7, 2007
Steve Simon

 

Recommendations from Sackett et al for evaluating a diagnostic test

*Blog post
2007
Diagnostic testing
There is a lot of controversy about diagnostic testing, and I have mentioned some of these controversies in other weblog entries. I wanted to review what the experts say…
Jul 2, 2007
Steve Simon

 

The stubborn insistence on placebos

*Blog post
2007
Placebos in research
The patients who volunteer for a randomized trial are sacrificing a great deal of autonomy. They giving up the right to determine which drug they get and they are ceding…
Jun 29, 2007
Steve Simon

 

How two bad control groups can add up to one good comparison

*Blog post
2007
Observational studies
Many observational studies are criticized (often deservedly) for having a bad control group. If you choose a bad control group, you create an unfair (apples to oranges)…
Jun 28, 2007
Steve Simon

 

The debate about historical control groups

*Blog post
2007
Broken link
Observational studies
Someone on the Evidence Based Medicine email discussion group asked about how to appraise a “before and after” design. This is effectively the same as using a historical…
Jun 27, 2007
Steve Simon

 

The trouble with apples and oranges

*Blog post
2007
Observational studies
Placebos in research
I am still working on the details of a presentation for the Kansas City University of Medicine and Biosciences. They want me to talk at lunch during the 2007 Homecoming CME…
Jun 25, 2007
Steve Simon

 

I deserve a promotion

*Blog post
2007
Professional details
Please note a related weblog entry: External scholars needed to review my promotion materials.
Jun 22, 2007
Steve Simon

 

Why the plus one in the percentile formula?

*Blog post
2007
Descriptive statistics
I was reviewing your page on the interquartile range and was wondering why the formula for the quartiles in particular and percentiles in general asks you to select the…
Jun 22, 2007
Steve Simon

 

Can the standard deviation be more than half of the range?

*Blog post
2007
Statistical theory
I was trying to work with some simple data sets to see how large I could make the standard deviation relative to the range. I know the standard deviation can never be larger…
Jun 22, 2007
Steve Simon

 

Publication Bias references

*Blog post
2004
Being updated
Here is a list of resources originally published in the category page of my old website. I want to restructure these and put them in separate pages with a common format.
Jun 19, 2007
Steve Simon

 

When bad control groups happen to good researchers

*Blog post
2007
Observational studies
Placebos in research
The Kansas City University of Medicine and Biosciences wants me to give a light humorous talk at lunch during the 2007 Homecoming CME and Reunion weekend. Somehow, they…
Jun 15, 2007
Steve Simon

 

Use of diagnostic tests for making clinical decisions

*Blog post
2007
Diagnostic testing
I’m giving a talk for the American College of Allergy, Asthma, and Immunology with the title “Use of diagnostic tests for making clinical decisions.” Here’s an abstract of…
Jun 15, 2007
Steve Simon

 

Seven different formulas for the odds ratio

*Blog post
2007
Writing research papers
I received an interesting email recently. Someone was studying the relationship between firearm suicides and veterans to answer the question: “Are veterans more likely to…
Jun 14, 2007
Steve Simon

Seven different formulas for the odds ratio

*Blog post
2007
Writing research papers
I received an interesting email recently. Someone was studying the relationship between firearm suicides and veterans to answer the question: “Are veterans more likely to…
Jun 14, 2007
Steve Simon

 

Accounting for cyclical trends in a regression model

*Blog post
2007
Linear regression
One of the doctors brought by a data set that showed the average volume of business (number of beds filled) in a month for 28 consecutive months starting in January 2005.…
Jun 13, 2007
Steve Simon

 

Illustrated case studies of research ethics and research fraud

*Blog post
2007
Ethics in research
I’ve written a fair number of case studies involving research ethics and research fraud for the Chance Wiki. I want to take some of this material and produce some web pages…
Jun 11, 2007
Steve Simon

 

Centering the data

*Blog post
2007
Data transformations
Why do we have to center the data before analyzing it? What would happen if we failed to center the data?*
Jun 8, 2007
Steve Simon

 

Calculating probabilities involving correlated normal variables

*Blog post
2007
Probability concepts
Someone on EDSTAT-L asked about a problem involving differences of independent normal random variables. I am simplifying the problem a bit, but it essentially asked a…
Jun 4, 2007
Steve Simon

 

Applying likelihood ratios in your head

*Blog post
2007
Diagnostic testing
Someone sent me a nice email complimenting my likelihood ratio slide rule.
Jun 1, 2007
Steve Simon

 

Using real examples in teaching statistics (May 30, 2007)

*Blog post
2007
Teaching resources
I am writing a book review and wanted to get some opinions from participants on EDSTAT-L about the tendency that this book (and many others) has for using hypothetical…
May 30, 2007
Steve Simon

 

May has been a slow month

*Blog post
2007
Website details
After a burst of activity, my work on the weblog has slowed down quite a bit this month. There are three reasons (excuses):
May 29, 2007
Steve Simon

 

Classic references in evidence based medicine

*Blog post
2007
Teaching resources
A couple of weeks ago, a regular correspondent (PG) on the Evidence Based Health email discussion group asked about what were the essential readings in Evidence Based…
May 16, 2007
Steve Simon

 

Choosing between two conflicting analyses

*Blog post
2007
Pvalues
Someone wrote in and asked about an analysis where there was only a limited amount of data. The simple analysis using an odds ratio produced a significant result (p=0.048).…
May 16, 2007
Steve Simon

 

Where can you find interesting case studies in Statistics?

*Blog post
2007
Teaching resources
Someone wrote in to the MedStats email discussion group and asked about where to find interesting articles with full free text and sufficient detail that students could…
May 2, 2007
Steve Simon

 

What to measure in a post-marketing surveillance study

*Blog post
2007
Clinical importance
I am volunteering as a data analyst in a post-marketing surveillance to assess the safety and efficacy of a drug. I’m not sure what to measure and how to measure it. Can you…
May 2, 2007
Steve Simon

 

Cohen’s Kappa with small cell sizes

*Blog post
2007
Measuring agreement
Small sample size issues
Someone on Edstat-L wrote in asking about using Cohen’ Kappa with a small sample size in some of the cells. Here’s an example:
Apr 26, 2007
Steve Simon

 

ANOM table for alpha=0.05, part 2

*Blog post
2007
Analysis of means
Here’s a table of critical values for analysis of means (ANOM) at an alpha level of 0.05. It is a continuation of the table
Apr 21, 2007
Steve Simon

 

Fitting a beta binomial model using BUGS

*Blog post
2007
Bayesian statistics
I’ve spent a bit of time trying to learn how to run a program called BUGS. The acronym stands for Bayes Using Gibbs Sampling. Here is my first serious attempt to run a BUGS…
Apr 17, 2007
Steve Simon

 

A simple illustration of the Metropolis algorithm

*Blog post
2007
Bayesian statistics
In many situations, you need to generate a random sample from a distribution that is rather complex. When simpler methods for generating a random sample don’t work, there…
Apr 13, 2007
Steve Simon

 

Special section for quotations

*Blog post
2007
Obsolete page
Website details
*Quotation
[Note: the organizational details of the current website differ from that described here.]
Apr 11, 2007
Steve Simon

 

When I talk about statistics

*Quotation
2007
Critical appraisal
When I talk to people about statistics, I find that they usually are quite willing to criticize dubious statistics–as long as the numbers come from people with whom they…
Apr 11, 2007
Steve Simon

 

IRB review of studies with methodological flaws

*Blog post
2007
Ethics in research
Someone (AK) wrote into the IRBForum asking about how the IRB should do when they discover methodological flaws in the proposed research. If everything else is in order…
Apr 10, 2007
Steve Simon

 

Quantifying the ability of dreams to predict the future

*Blog post
2007
Diagnostic testing
Someone wrote to me about a diary they had kept for the past eight years about their dreams. About every other month or so, a dream of theirs came true. I was asked if I…
Apr 10, 2007
Steve Simon

 

One of the naturalists had argued that

*Quotation
2007
Theory versus practice
One of the naturalists had argued that On the Origin of Species was too theoretical, that Darwin should have just “put his facts before us and let them rest.” In response…
Apr 9, 2007
Steve Simon

 

What is an adequate sample size for establishing validity and reliability?

*Blog post
2007
Measuring agreement
Sample size justification
Someone from Mumbai, India wrote in asking whether a sample of 163 was sufficiently large for a study of reliability and validity. This was for a project that was already…
Apr 9, 2007
Steve Simon

 

Calculating rates

*Blog post
2007
Poisson regression
Someone on the MedStats discussion group asked how to calculate a rate of needlestick incidents. The answer is quite simple, but there are a variety of possible responses.
Apr 6, 2007
Steve Simon

 

What makes a good diagnostic test?

*Blog post
2007
Diagnostic testing
I’ve been invited to give a talk at the annual meeting of the American College of Allergy, Asthma & Immunology. The tentative title of the talk is “What makes a good…
Apr 6, 2007
Steve Simon

 

useR! 2007 conference in Ames, Iowa

*Blog post
2007
R software
I may not be able to go to it, but the R community has an annual meeting, useR!, that will be held this year in Ames, Iowa from August 8-10. The web site for this conference (…
Apr 6, 2007
Steve Simon

 

Tracking adverse events during kidney biopsy, Part 2

*Blog post
2007
Adverse events
This is a major revision of a March 14, 2007 weblog entry.
Apr 5, 2007
Steve Simon

 

Further explanation about Type I and Type II errors

*Blog post
2007
Hypothesis testing
I got some feedback that my definitions of Type I > errors and Type II > errors would be > clearer if I specified what the actual hypothesis are. I wanted to > avoid symbols…
Apr 5, 2007
Steve Simon

 

The Seven Deadly Sins of Researchers

*Blog post
2007
Critical appraisal
I was reading an article in written by Steven Goodwin, The Seven Sins of Programmers, published in issue 17 of the Free Software Magazine and thought it would be fun to use…
Apr 4, 2007
Steve Simon

 

Reporting data analysis on transformed data

*Blog post
2007
Incomplete page
Statistical modeling
I’m confused by the use of transformations in Statistics. When you transform the data, the standard deviation is bound to be incorrect, even after you invert the…
Mar 28, 2007
Steve Simon

 

R Wiki

*Blog post
2007
R software
I use R software for a lot of my complex data analyses and have written up a few web pages about various things you can do with R. It turns out that R has a Wiki site, R Wiki
Mar 27, 2007
Steve Simon

 

IRB review of a pilot study

*Blog post
2007
Ethics in research
Pilot studies
Sample size justification
I am the new chair of the IRB at a county hospital. Many of the studies we review are pilot studies with small samples. I have been trying to locate criteria for the…
Mar 26, 2007
Steve Simon

 

Confidence intervals for count data

*Blog post
2007
Poisson regression
If you have data involving counts, you have several options for computing confidence intervals. All of these approaches rely on approximations to the Poisson distribution or…
Mar 22, 2007
Steve Simon

 

Some UNIX humor

*Blog post
2007
Statistical computing
The website www.netfunny.com has a lot of computer humor. Here’s one that caught my eye because I am taking a class in Bioinformatics and am learning a lot about UNIX.
Mar 22, 2007
Steve Simon

 

Interpretation of an odds ratio

*Blog post
2007
Logistic regression
Someone sent me some data on crime. In a sample of 2,957,239 people, 961 were criminals. 41 of the criminals were in the first group (who numbered 20,109). The remaining 920…
Mar 21, 2007
Steve Simon

 

What I’m working on right now

*Blog post
2007
Analysis of means
Bayesian statistics
Quality control
There are several research projects where I am actively looking for collaborators. I thought I’d outline these topics briefly here.
Mar 18, 2007
Steve Simon

 

Randomly dividing a dataset in R

*Blog post
2007
R software
I’m working with someone who wants to do a simple cross-validation of a statistcal procedure. One simple way to do this is to randomly divide a data set into two piece.…
Mar 16, 2007
Steve Simon

 

Randomly dividing a dataset in R

*Blog post
2007
R software
A regular contributor to EDSTAT-L (DR) mentioned the following interesting resource:
Mar 16, 2007
Steve Simon

 

Bad calculation of annual rate of return

*Blog post
2007
Wiki pages
The Chance Wiki has a section called “Forsooths.” This section presents quantitative errors in the popular press that are self-evident under careful examination. I found an…
Mar 15, 2007
Steve Simon

 

Thanks to all my proofreaders!

*Blog post
2007
Website details
Someone emailed me with a suggestion that I have said “increase” when I meant to say “decrease” and “decrease” when I meant to say “increase.” I looked at the page in…
Mar 14, 2007
Steve Simon

 

Tracking adverse events during kidney biopsy

*Blog post
2007
Adverse events
I have been helping a colleague who is interested in monitoring the safety of kidney biopsy events. He was kind enough to let me use his data set on my web pages in order to…
Mar 14, 2007
Steve Simon

 

Ignore weak evidence at your own peril

*Blog post
2007
Critical appraisal
I ran across an interesting article recently.
Mar 13, 2007
Steve Simon

 

Reviewing a paper on qualitative data analysis

*Blog post
2007
Qualitative research
I was asked by BMJ to review a paper that involved a qualitative data analysis. These reviews are confidential, so I don’t want to describe the paper in any detail. It is…
Mar 11, 2007
Steve Simon

 

Manipulation of peer-review publications by pharmaceutical companies

*Blog post
2007
Conflict of interest
This weblog entry provides some discussion points that I want to share in a seminar:
Mar 9, 2007
Steve Simon

 

How to draw a fishbone diagram

*Blog post
2007
Quality control
This is a condensed version of a handout
Mar 8, 2007
Steve Simon

 

Calculating a P control chart

*Blog post
2007
Broken link
Control charts
If you are collecting data on proportions with a consistent denominator for each proportion, then you can plot this data on a control chart. This type of chart is called a P…
Mar 7, 2007
Steve Simon

 

P control chart, answers to on your own exercises

*Blog post
2007
Control charts
On the web page Calculating a P control chart you were asked to calculate P charts for the following two data sets:
Mar 7, 2007
Steve Simon

 

Analysis of Means answers to on your own exercises

*Blog post
2007
Analysis of means
Incomplete page
On the web page
Mar 6, 2007
Steve Simon

 

Calculation of Analysis of Means limits

*Blog post
2007
Analysis of means
Incomplete page
This page shows some of the details for calculating an analysis of means (ANOM) chart.
Mar 6, 2007
Steve Simon

 

Review of statistical methods in The New England Journal of Medicine and Nature Medicine

*Blog post
2007
Human side of Statistics
The Kansas University Medical Center has a statistics journal club and this month, they reviewed an article
Mar 5, 2007
Steve Simon

 

ANOM table for alpha=0.05, part 1

*Blog post
2007
Analysis of means
Incomplete page
Here’s a table of critical values for analysis of means (ANOM) at an alpha level of 0.05.
Mar 4, 2007
Steve Simon

 

Handouts for quality control workshop

*Blog post
2007
Quality control
I am in charge of a workshop for the American Society for Andrology for their 32nd Annual Conference in Tampa Florida. This society holds a laboratory workshop every year…
Mar 2, 2007
Steve Simon

 

Analysis of Means calculations

*Blog post
2007
Analysis of means
Incomplete page
Analysis of Means (ANOM) are available for a wide range of data sets, and it is impossible to summarize all the applications of ANOM here. The goal on this web page is to…
Mar 2, 2007
Steve Simon

 

PharmedOUT website

*Recommendation
2007
Conflict of interest
In response to educational resources in medicine that are dominated by drug company support, a new website, PharmedOUT, has been formed. This site is developed by Adriane…
Mar 2, 2007
Steve Simon

 

Calculating an XBAR-S control chart

*Blog post
2007
Control charts
The following data represents a weekly evaluation of vaccine potency. The data is taken from
Mar 2, 2007
Steve Simon

 

XBAR-S control chart, answers to on your own exercise

*Blog post
2007
Control charts
On the web page
Mar 2, 2007
Steve Simon

 

Using a pocket calculator to compute a standard deviation

*Blog post
2007
Descriptive statistics
Most of the time, I let a computer program like SPSS compute quantities for me, but every now and then, I want to calculate a few simple statistics without the benefit of…
Mar 1, 2007
Steve Simon

 

Team exercise to illustrate ANOM calculations

*Blog post
2007
Broken link
Analysis of means
I am in charge of a workshop for the American Society for Andrology for their 32nd Annual Conference in Tampa Florida. This society holds a laboratory workshop every year…
Feb 28, 2007
Steve Simon

 

Stats

*Blog post
2007
Being updated
Website details
(To be added)
Feb 27, 2007
Steve Simon

 

Stats

*Blog post
2007
Website details
Being updated
(To be added)
Feb 27, 2007
Steve Simon

 

Stats

*Blog post
2007
Website details
(To be added)
Feb 27, 2007
Steve Simon

 

Formulas for cumulative Poisson and binomial probabilities

*Blog post
2007
Poisson regression
Probability concepts
I am updating some material about Poisson regression and noticed that some of the tests and confidence intervals rely on a percentile from a Chi-squared distribution or a…
Feb 19, 2007
Steve Simon

 

Searching through the Current Index to Statistics

*Blog post
2007
Information searching
I wanted to search for any recent references about teaching Bayesian statistics. The American Statistical Association has a nice resource for its members, the Current Index…
Feb 15, 2007
Steve Simon

 

Three simple rules to establish quality

*Blog post
2007
Broken link
Quality control
I received a recommendation to purchase a book (Process Quality Control, by Ellis Ott) and while searching for reviews of this book, found something called Ott’s Rules.…
Feb 15, 2007
Steve Simon

 

A recent contribution to Wikipedia and to the Chance Wiki

*Blog post
2007
Wiki pages
I’ve made some minor contributions from time to time in Wikipedia, a free encyclopedia on the web edited by volunteers. My previous work was on
Feb 15, 2007
Steve Simon

 

Watch out for ambiguous data

*Blog post
2007
Data management
Someone brought me a data set with some interesting values. It serves as a good example about why you need to carefully review simple descriptive statistics before you…
Feb 14, 2007
Steve Simon

 

Advice for searching in PubMed

*Blog post
2007
Incomplete page
Information searching
Trish Greenhalgh wrote a nice article about searching for medical information using PubMed.
Feb 11, 2007
Steve Simon

 

Compound interest and powers

*Blog post
2007
Statistical theory
In some of my mathematical calculations, I end up computing an expression that involves a number very close to one raised to a very large power. This term can often be…
Feb 11, 2007
Steve Simon

 

Resources for fMRI data analysis

*Blog post
2007
Imaging
I was asked to provide feedback on a grant that will use functional magnetic resonance imaging (fMRI) as one component of the research. This technique is used to quantify…
Feb 8, 2007
Steve Simon

 

When is a control chart not a control chart?

*Blog post
2007
Analysis of means
Control charts
Incomplete page
I found a pair of data sets on the web that represent counts and where one goal of the data collection is to see if any of the individual counts differ from the overall…
Feb 6, 2007
Steve Simon

 

Modular arithmetic and rounding in R

*Blog post
2007
R software
In certain programming situations, you need to perform calculations involving division that produce whole numbers as a result. For example, if you divided 27 by 4, you would…
Feb 1, 2007
Steve Simon

 

The danger of providing expert testimony when you are not an expert

*Blog post
2007
Human side of statistics
Sir Roy Meadow is an expert on child abuse, having published a landmark paper in 1977 on a condition known as Munchausen Syndrome by Proxy. An observation of his
Jan 31, 2007
Steve Simon

 

Not everything that can be counted

*Quotation
2007
Qualitative research
Not everything that can be counted counts, and not everything that counts can be counted. - Albert Einstein (1879-1955). Quote found in the January 31, 2006 issue of WXPnews.
Jan 31, 2007
Steve Simon

 

Do your own power and sample size calculations

*Blog post
2007
Sample size justification
Someone asked me for some power calculations and the problem was stated very tersely and completely.
Jan 30, 2007
Steve Simon

 

Fitting a difference in exponential functions

*Blog post
2007
Nonlinear regression
I was presented with a data set of sixteen subjects that showed a rise in values from zero to a maximum followed by gradual return of those values to zero for each subject.…
Jan 26, 2007
Steve Simon

 

Manipulating graphic images using a touchscreen interface

*Blog post
2007
Statistical computing
There is a cute video out showing some examples of manipulating graphic images using a touchscreen interface. In particular, the operator can expand images and zoom in by…
Jan 23, 2007
Steve Simon

 

Books that discuss Poisson regression

*Blog post
2007
Poisson regression
Someone on the MedStats discussion group asked about books discussing Poisson regression. If you want to use Poisson regression, you need an overview of the generalized…
Jan 19, 2007
Steve Simon

 

Tests of hypothesis and confidence intervals involving a correlation coefficient

*Blog post
2007
Linear regression
Suppose you compute a correlation coefficient from a sample of patients. Can you test a hypothesis about this correlation? Can you place confidence limits around this…
Jan 18, 2007
Steve Simon

 

Technometrics review of Statistical Evidence

*Blog post
2007
Professional details
The February 2007 issue of Technometrics has a review of my book, Statistical Evidence in Medical Trials. The review is not available on the web, unless you subscribe to…
Jan 16, 2007
Steve Simon

 

Resources describing biplots

*Blog post
2007
Categorical data
I’ve written some code in R to present a graphical summary of a complex data set using biplots. I write most of the code myself using the singular value decomposition…
Jan 15, 2007
Steve Simon

 

What can you do with 100 words?

*Blog post
2007
Wiki pages
I added another short entry to Chance News 23 about a dubious claim that 100 words are needed for half of all reading in English.
Jan 12, 2007
Steve Simon

 

Differences between the Chi-square test, Fisher’s Exact test, and logistic regression

*Blog post
2007
Logistic regression
I received an email from India (isn’t the Internet wonderful?) that asked me to comment on the differences between a Chi-square test, Fisher’s Exact test, and logistic…
Jan 9, 2007
Steve Simon

 

Can Google replace your doctor?

*Blog post
2007
Diagnostic testing
An article published in BMJ argues that Google searches can sometimes aid with developing an appropriate diagnosis of disease.
Jan 4, 2007
Steve Simon

 

Variable cluster sizes and their impact on sample size calculations

*Blog post
2007
Sample size justification
A recently published article in the International Journal of Epidemiology discusses sample size requirements for cluster randomized trials when the size of the cluster…
Jan 3, 2007
Steve Simon

 

Be sure to account for dropouts in your sample size calculation

*Blog post
2006
Sample size justification
I helped out a colleague with an NIH grant, and when the critique came back, it mentioned two issues that I should have been aware of. First, they pointed out the need for…
Dec 29, 2006
Steve Simon

 

What percentage of medical decisions are based on good evidence?

*Blog post
2006
Teaching resources
A correspondent on the evidence based health list noted a commonly quoted statistic that only 10% of all medical practices are based on solid evidence (e.g., randomized…
Dec 29, 2006
Steve Simon

 

Cherry picking the literature

*Blog post
2006
Systematic overviews
I have a relative who loves to send me articles supporting a particular religious and political viewpoint that he endorses. While that viewpoint he espouses is usually…
Dec 20, 2006
Steve Simon

 

Unusual advice about control charts

*Blog post
2006
Control charts
Someone sent me some recommended guidance on how to use a control chart and it included the following quote:
Dec 18, 2006
Steve Simon

 

Using focus groups to bridge the gap between research and practice

*Blog post
2006
Qualitative research
The Injury Prevention journal published a nice article on how to use focus groups to bridge the research-practice gap,
Dec 14, 2006
Steve Simon

 

Should/Can Statistical Consultants, be Independent?

*Blog post
2006
Human side of statistics
I attended a webinar, “Should (Can?) Statistical Consultants, be Independent?” presented by Janet Wittes.
Dec 14, 2006
Steve Simon

 

Mathematical and statistical challenges

*Blog post
2006
Statistical theory
A regular poster on the EDSTAT-L list (DR) mentioned an interesting page on the IBM website, www.research.ibm.com/ponder, that offers a monthly puzzle on mathematical…
Dec 13, 2006
Steve Simon

 

Evidence-based development of medical guidelines

*Blog post
2006
Teaching resources
An open source journal, Health Research Policy and Systems, has a series of articles on how to develop guidelines in a rigorous and evidence-base manner. Here are the first…
Dec 13, 2006
Steve Simon

 

Perfect isn’t quite good enough

*Blog post
2006
Small sample size issues
Someone wanted me to double check their calculations for Fisher’s Exact test. If the control group, 3 out of 10 patients experienced an unfortunate outcome. In the treatment…
Dec 12, 2006
Steve Simon

 

PharmaIQ talks

*Blog post
2006
Data mining
I attended the conference “Signal Detection and Data Mining” sponsored by PharmaIQ. Here are some notes I took during some of the talks.
Dec 6, 2006
Steve Simon

 

When are two events worrisome?

*Blog post
2006
Early stopping
I was attending a workshop on developing a risk management plan for a new drug. The presenter, Nawab Qizilbash from Oxon Clinical Epidemiology, gave an interesting example.…
Dec 4, 2006
Steve Simon

 

Manipulation of peer-review publications by pharmaceutical companies

*Blog post
2006
Ethics in research
I volunteered to give a talk at a local hospital, and the topic I’d like to discuss is “Manipulation of peer-review publications by pharmaceutical companies.” It would cover…
Nov 21, 2006
Steve Simon

 

A simple Bayesian model for accrual

*Blog post
2006
Accrual problems
Bayesian statistics
Rmarkdown code
Suppose you are a researcher in charge of a long term study. You plan to collect data on 120 patients. The goal is to finish your study in ten years, which means getting 12…
Nov 17, 2006
Steve Simon

 

The tension between scientific validity and ethical concerns

*Blog post
2006
Placebos in research
A question on the IRB Forum email discussion group (from RI) centered on the ethical concerns about using a placebo arm in a study involving control of pain. There are…
Nov 17, 2006
Steve Simon

 

Fitting a quadratic regression model

*Blog post
2006
Linear regression
Someone came in asking about how to examine for non-linear relationships among variables. In particular, they wanted to look for a U-shaped pattern where a little bit of…
Nov 16, 2006
Steve Simon

 

The complexities of having a variable number of measures per patient

*Blog post
2006
Multilevel models
A series of messages on the MedStats email discussion group emphasized the difficulty in analyzing data where subjects contribute a variable number of measurements to the…
Nov 16, 2006
Steve Simon

 

The danger of using humor on a web page

*Blog post
2006
Website details
I got a nice email yesterday from someone who had read my web page with a definition of a retrospective study.
Nov 14, 2006
Steve Simon

 

Incorporating risk factors into diagnostic test calculations

*Blog post
2006
Diagnostic testing
A contributor to the Evidence-Based Health email discussion group (PK) raised an interesting question about how to incorporate information about risk factors when applying…
Nov 9, 2006
Steve Simon

 

Technical Articles and Reports by David Heiser

*Blog post
2006
Websites
David A. Heiser, a regular contributor to EDSTAT-L, has a nice web page at that covers some of the numerical accuracy and computational problems inherent in many statistical…
Nov 7, 2006
Steve Simon

 

Rebutting an expert reviewer

*Blog post
2006
Human side of statistics
A regular contributor to EDSTAT-L (KW) asked about how to handle a bad peer review of an article that a colleague had submitted. The reviewer appeared to get the definitions…
Nov 7, 2006
Steve Simon

 

Materials for Signal Detection and Data Mining Strategies conference

*Blog post
2006
Administrative details
I had a November 6 deadline to send materials to PhamaIQ for the two talks I am giving at the Signal Detection and Data Mining Strategies conference being held in London…
Nov 6, 2006
Steve Simon

 

Medline is a very busy place

*Blog post
2006
Information searching
According to a National Library of Medicine announcement
Nov 6, 2006
Steve Simon

 

Additions and improvements to my web pages

*Blog post
2006
Broken link
Obsolete pages
Website details
Sample size justification
This page is obsolete. I am keeping it around for nostalgic reasons. Some of the links on this page are broken and I will try to fix them when I have time.
Nov 2, 2006
Steve Simon

 

Statistical concerns in research studies involving children

*Blog post
2006
Children in research
The statistical design and analysis issues for research involving children are not really that much different than for adults, but there are three areas that you need to pay…
Nov 2, 2006
Steve Simon

 

Parametric tests for a ratio

*Blog post
2006
Unusual data
Dear Professor Mean, I computed a variable, Y3, which is the ratio of two other variables, Y1 and Y2. Can I use a parametric test on this ratio?
Oct 27, 2006
Steve Simon

 

Adjusting a variable for age and sex

*Blog post
2006
Covariate adjustment
Someone asked me how to adjust bone mineral density (BMD) for age and sex. I presume that BMD changes as children grow (or as adults age) and that BMD is different for men…
Oct 26, 2006
Steve Simon

 

Searching for pediatric articles on Medline

*Blog post
2006
Children in research
Information searching
A recent publication
Oct 26, 2006
Steve Simon

 

Is a 10% shortfall in sample size critical?

*Blog post
2006
Confidence intervals
Sample size justification
Dear Professor Mean, I’m reviewing a paper where they did a power calculation based on 60 patients per group, but in the research study, they ended up only getting 55/58 per…
Oct 23, 2006
Steve Simon

 

A simple example of a mixed linear regression model

*Blog post
2006
Multilevel models
I want to illustrate how to run a simple mixed linear regression model in SPSS. I will use some data on the plasma protein levels of turtles at baseline, after fasting 10…
Oct 18, 2006
Steve Simon

 

Ethical concerns about research in children

*Blog post
2006
Children in research
Pediatric research must balance two important social and ethical goals. First, scientific progress that includes issues important to children will by necessity require that…
Oct 17, 2006
Steve Simon

 

Case studies for differences in research in children

*Blog post
2006
Children in research
I want to include several case studies about issues relating to the differences in research in children. Here are some articles with full free text on the web which I think…
Oct 16, 2006
Steve Simon

 

Mathematical derivation of the odds form of Bayes theorem

*Blog post
2006
Diagnostic testing
I had included some rather technical details on my web page about likelihood ratios, but I thought it would be best to move it to a separate page. Define the following terms:
Oct 16, 2006
Steve Simon

 

Differences between children and adults

*Blog post
2006
Children in research
A recently published report from the Institute of Medicine, Emergency Care for Children--Growing Pains, has a very nice table in the introduction that highlights some of the…
Oct 13, 2006
Steve Simon

 

Frank Harrell’s Philosophy of Biostatistics

*Blog post
2006
Modeling issues
There are a lot of people in the world who are a lot smarter than I am and it is always a humbling experience when I recognize how little I really know.
Oct 10, 2006
Steve Simon

 

Book reviews for Statistical Evidence

*Blog post
2006
Statistical evidence
The International Journal of Epidemiology published a review of my book, Statistical Evidence in Medical Trials, in their September 15, 2006 issue. You need to be a…
Oct 5, 2006
Steve Simon

 

My second grant, part 3

*Blog post
2006
Accrual problems
I just finished my second grant, which I gave the title “Estimating delays in completion of IRB approved and KBR supported research studies” The two acronyms, IRB and KBR…
Oct 2, 2006
Steve Simon

 

Improvements to weblog categories

*Blog post
2006
Website details
With over a thousand web pages, I need a good way of letting people find related topics on my website. I’ve added categories to my weblog entries, and now I want to link…
Sep 25, 2006
Steve Simon

 

Is my confidence interval too wide?

*Blog post
2006
Clinical importance
Confidence intervals
Dear Professor Mean, Is there a rule of the thumb to judge if a 95% CI is wide or narrow?

I tell a story about a researcher who gets a six year, ten million dollar NIH…
Sep 21, 2006
Steve Simon

 

Two talks for PharmaIQ

*Blog post
2006
Children in research
I may be giving a couple of talks for for PharmaIQ, a division of the International Quality & Productivity Center (IQPC). The first has the title “Signal Detection…
Sep 19, 2006
Steve Simon

 

Oops! I found statistical significance in my pilot study

*Blog post
2006
Early stopping
Dear Professor Mean, I ran a pilot study to help me estimate the sample size for a larger study. There were 15 patients in each arm of the pilot, and when I analyzed the…
Sep 18, 2006
Steve Simon

 

Special issues for research involving children

*Blog post
2006
Ethics in research
Research is difficult enough, but it becomes more difficult when the research involves children. The issues that you need to consider are physiologic, ethical, and…
Sep 15, 2006
Steve Simon

 

Resources for the use of Statistical Process Control in Healthcare

*Blog post
2006
Quality control
Someone on the MedStats email discussion group asked for resources that “explain the use of SPC (statistical process control) to analyze quality indicators in a healthcare…
Sep 15, 2006
Steve Simon

 

Pharmacogenetics Research Network

*Blog post
2006
Genetic data analysis
I received an email today discussing a special conference being held by the the Pharmacogenetics Research Network (PGRN). It’s an “invitation only” conference, so I must…
Sep 14, 2006
Steve Simon

 

Ambiguous nature of the word “risk”

*Blog post
2006
Critical appraisal
A recent discussion on the Evidence-Based Health email discussion group focused on the word “risk”. It means harmful event (risks versus benefits) as well as a probability…
Sep 13, 2006
Steve Simon

 

Email discussion groups

*Blog post
2006
Teaching resources
An email discussion group is a collection of individuals with a common interest who supply their email address to a common site, typically called a listserver. When…
Sep 13, 2006
Steve Simon

 

My second grant, part 2

*Blog post
2006
Accrual problems
I took a three day workshop on grant writing and prepared a draft grant as part of the student exercises in that class. It’s not in the format that I need to use, but it…
Sep 13, 2006
Steve Simon

 

Graphics options in R

*Blog post
2006
Graphical display
R software
When you are producing graphics in R, the default option does not save your graphs for later review. You can change this in several ways. My comments will discuss the…
Sep 12, 2006
Steve Simon

 

Postmodern thought and evidence based medicine

*Blog post
2006
Teaching resources
A recently published article:
Sep 7, 2006
Steve Simon

 

Rules for rounding numbers

*Blog post
2006
Descriptive statistics
When you are reporting means and percentages from a descriptive data analysis, you should round your data to make it more readable. Ideally, you should show only two…
Sep 7, 2006
Steve Simon

 

Continuous monitoring of the number needed to harm

*Blog post
2006
Adverse events
The continuing review of clinical trials has to address “good news” issues. Does one arm of the study show substantially better efficacy? Does one arm of the study have a…
Sep 2, 2006
Steve Simon

 

Changing page breaks in SPSS

*Blog post
2006
SPSS software
SPSS often chooses some unusual and unfortunate places to make a page break. You can fix this, according to a helpful soul on the SPSSX-L listserv (MG). Just tell SPSS never…
Aug 31, 2006
Steve Simon

 

Wikipedia entry on Binomial Confidence Interval, Part 3

*Blog post
2006
Wiki pages
Here’s some additional material that I will add to the Wikipedia entry on Binomial Proportion Confidence Interval.
Aug 29, 2006
Steve Simon

 

Citing statistical software in research papers

*Blog post
2006
Statistical computing
On of the most common questions I get is how to properly acknowledge the use of a program like SPSS in a research publication. In a series of messages in the MedStats discuss…
Aug 25, 2006
Steve Simon

 

Wikipedia entry on Binomial Confidence Interval, Part 2

*Blog post
2006
Wiki pages
Here’s my first attempt to improve the Wikipedia entry on the binomial confidence interval. I start by simplifying and improving the introduction
Aug 22, 2006
Steve Simon

 

Quality control humor

*Blog post
2006
Quality control
It is important in any quality improvement process to define precisely what it is that you are trying to improve. Sloppy and imprecise definitions will make it hard for you…
Aug 20, 2006
Steve Simon

 

An exact confidence interval for a binomial proportion

*Blog post
2006
Confidence intervals
A researcher came into my office this morning with some data that was strongly negative. Out of 15 patients, none showed a detectable improvement after the use of a…
Aug 18, 2006
Steve Simon

 

More than one thousand web pages now available on my site

*Blog post
2006
Website details
When you do a global search and replace in Frontpage, it offers a page count of all the pages that it searches. Sometime in the past month, I exceeded one thousand pages.…
Aug 16, 2006
Steve Simon

 

American Statistical Association Traveling Course committee

*Blog post
2006
Professional details
I volunteered to be the new chair of the Traveling Course committee of the American Statistical Association (ASA). The ASA recruits speakers who offer a one day course on an…
Aug 15, 2006
Steve Simon

 

When should you worry about recall bias?

*Blog post
2006
Observational data
Dear Professor Mean, I am studying reports of early health concerns in a group of children with a chronic disease compared to a matched group of healthy controls. I believe…
Aug 3, 2006
Steve Simon

 

Sales figures for Statistical Evidence in Medical Trials

*Blog post
2006
Statistical evidence
I get twice yearly data on sales, and the first of these arrived today. I’ve sold 230 copies, which is not bad for a short time frame. I updated my page on the book and…
Aug 2, 2006
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Statistical evidence book
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 2, 2006
Steve Simon

 

R libraries for sample size justification

*Blog post
2006
R software
Sample size justification
There are a lot of good commercial and free sources for sample size justification. Note that most people use the term power calculation, but there is more than one way to…
Jul 28, 2006
Steve Simon

 

My second grant

*Blog post
2006
Accrual problems
I’m in the final stretch of writing a grant to submit to the Kansas City Area Life Sciences Institute.
Jul 26, 2006
Steve Simon

 

Using a colloquial tone in a grant application

*Blog post
2006
Grant writing
As I have mentioned many times in this weblog, I am writing a grant. A rough draft of the grant is available in PDF format. If you have feedback, I’d love to hear it by…
Jul 25, 2006
Steve Simon

 

Selecting randomly from a list

*Blog post
2006
Randomization
A common task in research is to randomly select a subgroup from a list. For example, you have the names of 26 patients, Alpha, Bravo, Charlie, Delta, etc. Suppose you want…
Jul 18, 2006
Steve Simon

 

Questions a volunteer should ask before participating in a clinical trial

*Blog post
2006
Ethics in research
A regular contributor to the IRBForum (MG), wrote a nice list of questions that a volunteer should ask before they decide to participate in a clinical trial.
Jul 18, 2006
Steve Simon

 

Seminar notes. Missing values in a dose response model

*Blog post
2006
Nonlinear regression
One of the talks at the 18th Annual Applied Statistics in Agriculture Conference, sponsored by Kansas State University was “Dose-Response Modeling with Marginal Information…
Jul 17, 2006
Steve Simon

 

Seminar notes. Issues in the analysis of mixed linear models

*Blog post
2006
Multilevel models
The keynote address at the 18th Annual Applied Statistics in Agriculture Conference, sponsored by Kansas State University was “Random Observations with Mixed Feelings”…
Jul 17, 2006
Steve Simon

 

Seminar notes. Working with molecular biologists

*Blog post
2006
Human side of statistics
One of the talks at the 18th Annual Applied Statistics in Agriculture Conference, sponsored by Kansas State University was “A visual aid to help a statistician work with a…
Jul 17, 2006
Steve Simon

 

Seminar notes. Adjustments for multiple comparisons

*Blog post
2006
Analysis of variance
One of the talks at the 18th Annual Applied Statistics in Agriculture Conference, sponsored by Kansas State University was “A Comparison of Multiple Tests Procedures…
Jul 17, 2006
Steve Simon

 

Fraudulent images in research

*Blog post
2006
Ethics in research
Fraud in research is a big problem. One issue that has come up recently is that graphical images can be “Photoshopped” to present the image in a way that does not truly…
Jul 12, 2006
Steve Simon

 

When can a conservative trust a liberal information source (and vice versa)

*Blog post
2006
Conflict of interest
I have a brother-in-law who loves to debate politics and religion. He always takes an aggressively conservative stand (I’m a flaming liberal, but try not to mention politics…
Jul 10, 2006
Steve Simon

 

Possible sources of funding for my grant

*Blog post
2006
Accrual problems
The NIH has a Request for Application (RFA) titled Research on Research Integrity (R01). The full text of this announcement is on the web at
Jul 6, 2006
Steve Simon

 

Stopping rules for a Data Safety Monitoring Plan

*Blog post
2006
Early stopping
If a research study requires a DSMP (Data Safety Monitoring Plan), that plan should outline conditions that would cause a study to end early. It is difficult to specify what…
Jul 5, 2006
Steve Simon

 

Some resources for Analysis of Means

*Blog post
2006
Analysis of means
One of the techniques recommended by Davis Balestracci when he visited CMH in June 2006 was Analysis of Means, which often is abbreviated ANOM. You can use ANOM much like a…
Jun 30, 2006
Steve Simon

 

What is block randomization

*Blog post
2006
Randomization
Several people have asked me about block randomization, and while I discuss it briefly on several of my web pages, there is a better definition on the Consort Statement web…
Jun 30, 2006
Steve Simon

 

Likelihood software for clinical trials

*Blog post
2006
Statistical computing
A member of our local IRB forwarded a press release announcing new software that would revolutionize the conduct of clinical trials. The company is called Analytical Edge…
Jun 29, 2006
Steve Simon

 

The problem with ranking ordinal scales

*Blog post
2006
Unusual data
When I was young and naive, I thought that anytime you encountered ordinal data, it would make the most sense to use a test statistic based on ranks, such as the…
Jun 29, 2006
Steve Simon

 

Colors for R graphs

*Blog post
2006
Graphical display
R software
I tend to use color sparingly in graphs because most of my graphs end up in black and white in the final production. Even on my web pages - which appear in color - I try to…
Jun 28, 2006
Steve Simon

 

Resources for Item Response Theory

*Blog post
2006
Statistical computing
One area that I would like to investigate when I have time is Item Response Theory (IRT). This is an approach that is sometimes called a latent trait model or a Rasch model…
Jun 28, 2006
Steve Simon

 

Slash and burn models

*Blog post
2006
Modeling issues
I received an email question about developing a logistic regression model with some interaction terms. One of the interaction terms was statistically significant but one or…
Jun 26, 2006
Steve Simon

 

Using a charge of fraud to achieve a political end

*Blog post
2006
Ethics in research
There was an interesting paper published recently:
Jun 23, 2006
Steve Simon

 

Applications of the CUSUM chart

*Blog post
2006
Accrual problems
Control charts
I am interested in investigating the use of CUSUM charts in monitoring accrual rates, drop out rates, and adverse event rates in a clinical trial. Some references which I…
Jun 20, 2006
Steve Simon

 

Auditing for data entry errors

*Blog post
2006
Data management
There was an interesting query on the MedStats list about the appropriate sample size for an audit. This person had entered 1,500 records and wanted to check a sample of…
Jun 20, 2006
Steve Simon

 

Putting a human face on Evidence Based Medicine

*Blog post
2006
Teaching resources
A correspondent (BD) on the Evidence Based Health email discussion group pointed out the following web site:
Jun 20, 2006
Steve Simon

 

Philosophy of teaching

*Blog post
2006
Teaching resources
The email discussion group, EDSTAT-L, has had an extended discussion of teaching philosophy. I do some teaching myself, and I must admit that I don’t think nearly enough…
Jun 20, 2006
Steve Simon

 

Withholding Personal Health Information from a patient

*Blog post
2006
Privacy in research
An interesting discussion on the IRBForum related to a statement in an informed consent document that informed the patient that PHI (Personal Health Information) would be…
Jun 20, 2006
Steve Simon

 

Seminar notes. Confidence intervals for a variance ratio

*Blog post
2006
Analysis of variance
One of the talks at the 18th Annual Applied Statistics in Agriculture Conference, sponsored by Kansas State University was “Selecting the Best Confidence Interval for a…
Jun 17, 2006
Steve Simon

 

New entry in the Chance Wiki

*Blog post
2006
Wiki pages
I just posted a new article in the Chance Wiki:
Jun 7, 2006
Steve Simon

 

Seminar on control charts and adverse events

*Blog post
2006
Accrual problems
I took some time to expand my May 30, 2005 weblog entry on accrual rates and developed a seminar which I will present to the Statistics journal club at KUMC today.The handout…
Jun 5, 2006
Steve Simon

 

An amusing correlation

*Blog post
2006
Linear regression
I always like simple amusing examples that illustrate an important statistical point. An email by JW on EDSTAT-L offer a couple of examples.
Jun 5, 2006
Steve Simon

 

Methods for haplotype analysis

*Blog post
2006
Genetic analysis
I am not an expert on haplotype analysis, but as I understand it, a haplotype is a combination of several SNPs (Single Nucleotide Polymorphisms) that show a stronger…
May 31, 2006
Steve Simon

 

Monitoring accrual rates

*Blog post
2006
Accrual problems
This scenario is based on real data, but has been adapted slightly to serve as an illustration of the use of control charts in monitoring a clinical trial.
May 30, 2006
Steve Simon

 

Interesting stuff for the month of May

*Blog post
2006
Interesting stuff
Interesting quotes
Note: any quotations on this page have been moved to Category: Interesting quotes.
May 30, 2006
Steve Simon

 

Relationship between the standard deviation and the sample size

*Blog post
2006
Descriptive statistics
Dear Professor Mean, I have a data set that is accumulating more information over time. When I estimate the standard deviation for one of the outcomes in this data set…
May 26, 2006
Steve Simon

 

Upcoming talks about control charts

*Blog post
2006
Adverse events
I am working on some ideas for a grant to use control charts to track adverse events in clinical trials. I also envision the possibility of using control charts as a warning…
May 25, 2006
Steve Simon

 

Using APR-DRGs for risk adjustment

*Blog post
2006
Covariate adjustment
The 3M company, famous for Post-It notes, among other things, has a division for health information systems. One of their products is software that produces classifications…
May 24, 2006
Steve Simon

 

You won’t have Steve Simon to kick around anymore

*Blog post
2006
Professional details
The results of the election of officers for the American Statistical Association came out today, and sad to say, I came in second in a two person race. I was running for…
May 24, 2006
Steve Simon

 

Lost files

*Blog post
2006
Data management
I work on these web pages from my desktop computer and two different laptop computers. I also have an Administrative Assistant who will sometimes update my web pages from…
May 23, 2006
Steve Simon

 

Can the p-value actually equal 1.0?

*Blog post
2006
Pvalues
Dear Professor Mean, I have a data set that compares the proportions in two groups. In the first group, the proportion is 19% (5/26). In the second group, the proportion is…
May 23, 2006
Steve Simon

 

Another regular expression tip

*Blog post
2006
Data management
I had a large text file and I had to find the first example of a line that did NOT begin with the letter A. That’s easier said than done, but you can use some special…
May 23, 2006
Steve Simon

 

Using regular expressions to insert line breaks

*Blog post
2006
Data management
I had to change a file written in XML format. The file was pretty easy to manipulate except that it had no line breaks in it. It was a single line of text with a length of…
May 18, 2006
Steve Simon

 

Searching high level sources first

*Blog post
2006
Information searching
When you have to perform a search for the evidence, it pays to look at high level sources first. A recent discussion on the Evidence Based Health mailing list produced a…
May 17, 2006
Steve Simon

 

Using a web site to promote your book

*Blog post
2006
Statistical evidence
Someone on the MedStats email discussion group asked about how you use a web page to provide things like
May 10, 2006
Steve Simon

 

Always ask why

*Blog post
2006
Human side of statistics
I have a three year old boy at home and he’s learned that one way to keep the conversation going with an adult is to simply ask the question, “Why?”
May 8, 2006
Steve Simon

 

What constitutes a conflict of interest?

*Blog post
2006
Conflict of interest
I am a member of a committee that helps researchers set up Data Safety and Monitoring Boards (DSMBs) for research projects at Kansas University Medical Center (KUMC). The…
May 4, 2006
Steve Simon

 

Data mining and drug safety

*Blog post
2006
Adverse events
I am very interested in safety issues, especially in the continuing review/interim analysis of clinical trials. It turns out that S-plus is targeting drug safety as a…
May 4, 2006
Steve Simon

 

A simple application of propensity scores

*Blog post
2006
Covariate adjustment
In many research studies, you do not have the opportunity to randomly assign an exposure variable. The influence of the exposure variable on the outcome variable can…
Apr 26, 2006
Steve Simon

 

Surviving Statistical Spitting Matches

*Blog post
2006
Human side of statistics
I generally dislike an outline or bullet format for presenting information, but I came across a website
Apr 25, 2006
Steve Simon

 

Abstainer errors in study of alcohol abuse

*Blog post
2006
Diagnostic testing
Observational studies
A correspondent in the MedStats email discussion group (RR), mentioned an interesting example of problems in defining groups in observational studies. The actual publication…
Apr 19, 2006
Steve Simon

 

Giving credit where credit is due

*Blog post
2006
Website details
A lot of the material that I present on these web pages comes from reading various email discussion groups. I normally try to put in a plug for the groups when I can, but I…
Apr 19, 2006
Steve Simon

 

Univariate Model Based Clustering

*Blog post
2006
Cluster analysis
Back in 2001, I attended an excellent short course on a new approach to cluster analysis taught by Adrian Raftery and Chris Fraley at the Joint Statistics Meetings. Their…
Apr 18, 2006
Steve Simon

 

Blindfolded Donkey

*Blog post
2006
Outliers
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

The Busy Tailor

*Blog post
2006
Quality improvement
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

Three new koans

*Blog post
2006
Teaching resources
Over the weekend, I wrote three new koans.
Apr 17, 2006
Steve Simon

 

Ninety Nine Samples

*Blog post
2006
Confidence intervals
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

The Only True Path

*Blog post
2006
Randomization in research
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

Topic list is complete!

*Blog post
2006
Website details
It took a while, but I produced a topic list for every entry in my weblog. I may change some of these topics from time to time. The biggest advantage of placing a topic on…
Apr 17, 2006
Steve Simon

 

Useless Gifts

*Blog post
2006
Confidence intervals
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

*Blog post
2006
Hypothesis testing
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

Wax Fruit

*Blog post
2006
Confidence intervals
Statistical koans
Earlier versions are here and here.
Apr 17, 2006
Steve Simon

 

Placing the symbol X-bar in a document

*Blog post
2006
Teaching resources
Someone asked me how to place the symbol X-bar into a word processing document. This is tricky to do because there is nothing in the Symbol font that works and most word…
Apr 17, 2006
Steve Simon

 

Interesting websites, publications and quotes for the month of April

*Blog post
2006
Interesting stuff
Interesting quotes
Note: any quotations on this page have been moved to Category: Interesting quotes.
Apr 12, 2006
Steve Simon

 

The Healthcare Cost and Utilization Project

*Blog post
2006
Secondary data analysis
On April 20, I will be attending a webcast sponsored by the Agency for Healthcare Research and Quality (AHRQ) on a large data set they collected, the Healthcare Cost and…
Apr 11, 2006
Steve Simon

 

What is a beta coefficient?

*Blog post
2006
Linear regression
When you are examining the relative impact of several independent variables on an outcome variable, the estimated slopes may be deceptive. A variable with a wide range might…
Apr 4, 2006
Steve Simon

 

When is a co-authorship warranted?

*Blog post
2006
Human side of statistics
I am co-author on over 60 papers and have helped with the publication of many more papers. What does it take to get a co-authorship? I don’t quibble a lot about this, but it…
Apr 4, 2006
Steve Simon

 

Can you use the coefficient of determination for categorical variables?

*Blog post
2006
Linear regression
Dear Professor Mean, How can you compute a coefficient of determination (R squared) for a model that has a dichotomous variable? I thought that you could only compute this…
Apr 4, 2006
Steve Simon

 

Interpretation of the correlation coefficient

*Blog post
2006
Linear regression
There are many “rules of thumb” about how to interpret a correlation coefficient. They vary slightly from one to another, but all say about the same thing. Here’s a couple…
Apr 4, 2006
Steve Simon

 

Articles on Bayesian data analysis

*Blog post
2006
Bayesian statistics
Bayesian statistics
The Journal of Data Science has a couple of interesting Bayesian papers in the April 2006 issue.
Mar 30, 2006
Steve Simon

 

Contradictory research

*Blog post
2006
Critical appraisal
The Washington Post published an article that gets to the heart of the difficulty with Evidence Based Medicine. The URLs for these newspaper sites are always a bit…
Mar 30, 2006
Steve Simon

 

How many charts should I pull?

*Blog post
2006
Sample size justification
I got a question from someone doing a quality review. She needs to pull a certain number of medical records out of 892 and see whether the doctors followed the clinical…
Mar 30, 2006
Steve Simon

 

The role of a statistician on an IRB

*Blog post
2006
Human side of statistics
Someone on the IRBForum wrote in and asked what guidance their IRB could offer to a statistician who was just assigned to an Institutional Review Board (IRB). There were…
Mar 29, 2006
Steve Simon

 

New koan page

*Blog post
2006
Website details
I have consolidated the four statistical koans on a new page:
Mar 29, 2006
Steve Simon

 

Proper treatment will cure a cold in seven days, but

Quotation
2006
Evidence Based Medicine
Proper treatment will cure a cold in seven days, but left to itself a cold will hang on for a week. Henry G. Felsen, as quoted in E. S. Roach. Complementary and alternative…
Mar 29, 2006
Steve Simon

 

Small sample size, yet again

*Blog post
2006
Small sample size issues
Dear Professor Mean, Is there any statistical test/method that will allow you to make statistically significant conclusions from a sample of nine? Someone was trying to tell…
Mar 29, 2006
Steve Simon

 

Statistical koan #4

*Blog post
2006
Teaching resources
A visit from a thief.
Mar 26, 2006
Steve Simon

 

Seminar notes, Creating More Effective Graphics

*Blog post
2006
Descriptive statistics
I attended a web seminar, “Creating More Effective Graphs,” taught by Michael O’Connell and Naomi Robbins and sponsored by Insightful Software, the makers of S-plus.
Mar 24, 2006
Steve Simon

 

Examples of a fishbone diagram

*Blog post
2006
Quality improvement
This page is obsolete. Please see http://www.pmean.com/06/fishbone.html.
Mar 24, 2006
Steve Simon

 

My ten favorite books, #10

*Blog post
2006
Good books
A recently purchased book is worth mentioning, and it will probably make my Top Ten list. It has a very good section on how to properly apply diagnostic tests in the real…
Mar 17, 2006
Steve Simon

 

Crash Course in Spss for Windows

*Blog post
2006
Interesting books
SPSS software
Crash Course in Spss for Windows: Updated for Versions 10, 11, 12 And 13. (2006-03-16) Andrew M. Colman, Briony Pulford. ISBN: 1405145315 Publisher: Blackwell Publishers -…
Mar 16, 2006
Steve Simon

 

Statistical koan #3

*Blog post
2006
Teaching resources
The blindfolded donkey.
Mar 16, 2006
Steve Simon

 

Post hoc comparisons

*Blog post
2006
Analysis of variance
Note: It’s been a while since I last used the “Ask Professor Mean” format on these web pages, and I can’t think of a good reason why I abandoned that format. I just saw a…
Mar 15, 2006
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Statistical evidence book
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 15, 2006
Steve Simon

 

Software for structural equations models

*Blog post
2006
Statistical computing
A recent email on the Medstats discussion group discussed software for structural equations models. Some of the packages mentioned were:
Mar 14, 2006
Steve Simon

 

More on the Emily Rosa experiment

*Blog post
2006
Critical appraisal
One of the more interesting research studies from an Evidence-Based Medicine perspective started out as a simple science fair project by a fourth grade student. Emily Rosa…
Mar 10, 2006
Steve Simon

 

Poisson regression? Maybe not!

*Blog post
2006
Poisson regression
I get a lot of questions about Poisson regression, even though I have very little about it on my web pages. My guess is that there is even less information out there on the…
Mar 10, 2006
Steve Simon

 

Propensity scores

*Blog post
2006
Covariate adjustment
When I have time, I want to describe the use of propensity scores and show some examples. Propensity scores offer a simple and effective way to correct for covariate…
Mar 10, 2006
Steve Simon

 

What is construct validity?

*Blog post
2006
Measuring agreement
Someone asked me to define face validity, criterion validity, and construct validity. That’s a tall order. In general, validity means that a measurement that we take…
Mar 8, 2006
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Statistical evidence book
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 8, 2006
Steve Simon

 

Best EBM articles in 2005

*Blog post
2006
Teaching resources
One of the regular contributors to the Evidence Based Health email discussion group asked what we felt were the Best EBM methods papers in 2005. I’ll report on the articles…
Mar 6, 2006
Steve Simon

 

Update on my book, Statistical Evidence in Medical Trials

*Blog post
2006
Statistical evidence
Although I was expecting my book to appear sometime in February, a quick search of the Internet shows that March 31, 2006 may be a more realistic publication date. I have an…
Feb 28, 2006
Steve Simon

 

To be updated

*Blog post
2008
Being updated
Statistical evidence book
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 28, 2006
Steve Simon

 

Statistical koan #2

*Blog post
2006
Teaching resources
I got some limited feedback from EDSTAT-L about using koans to illustrate difficult and subtle statistical concepts, and at least one person thought that this device would…
Feb 28, 2006
Steve Simon

 

Statistical koans

*Blog post
2006
Teaching resources
Update: Check out my koan page.
Feb 27, 2006
Steve Simon

 

Difficulties in generalizing

*Blog post
2008
Being updated
Extrapolations in research
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 15, 2006
Steve Simon

 

Difficulties in generalizing research

*Blog post
2006
Extrapolations in research
I found this information thanks to an email in the Evidence-Based Health email discussion group. Someone asked if there was any empirical evidence that the setting of a…
Feb 15, 2006
Steve Simon

 

Meta-analysis and diagnostic tests

*Blog post
2006
Systematic overviews
I will be giving a talk at the graduate seminar series for the department of Mathematics and Statistics at UMKC on February 23. It will be a combination of material from the…
Feb 14, 2006
Steve Simon

 

Checking a Chi-square test

*Blog post
2006
Logistic regression
Someone preparing a critique of a research article wanted to check the accuracy of the statistics in that article. They noted that in a group of 37 patients without the…
Feb 13, 2006
Steve Simon

 

What makes a good book? A sense of humor.

*Blog post
2006
Good books
I was recently asked to evaluate a book proposal, and although I have not finished it, it made me think about what makes a book good. There are several things that I look…
Feb 13, 2006
Steve Simon

 

Reporting serious adverse events

*Blog post
2006
Adverse events
The FDA held a meeting on March 21, 2005 soliciting opinions about how adverse events should be reported to Institutional Review Boards (IRBs).
Feb 3, 2006
Steve Simon

 

Learning more about control charts

*Blog post
2006
Control charts
Someone asked me about resources for learning how to use control charts. I have a web page that talks about quality control in general and shows some of the computational…
Feb 1, 2006
Steve Simon

 

An Ensembl search

*Blog post
2006
Microarray analysis
While working on a microarray experiement with a researcher, we had to find a bit of information about a gene with the gene symbol NCOA3. We went to the Ensembl web site (www…
Feb 1, 2006
Steve Simon

 

How do the various clustering algorithms work?

*Blog post
2006
Cluster analysis
I’m working with someone on some clustering models for his microarray experiment. He asked how the various clustering algorithms work.
Jan 31, 2006
Steve Simon

 

More lessons learned the hard way

*Blog post
2006
Data management
The more I do, the more I realize how little I have thought about how to properly conduct a statistical analysis. One lesson I thought I had learned was that it costs next…
Jan 31, 2006
Steve Simon

 

Recent developments in searching for evidence

*Blog post
2006
Information searching
Dean Giustini publishes a web log, the UBC Google Scholar Blog, that covers recent developments and improvements in searching for evidence.
Jan 31, 2006
Steve Simon

 

Real-life examples of survey mistakes

*Blog post
2006
Survey design
Tzippy Shocat was nice enough to forward a link to an article that she wrote for the iSixSigma website (www.isixsigma.com), titled “Tips for Getting the Most from Six Sigma…
Jan 31, 2006
Steve Simon

 

A simple function for a Biplot in R

*Blog post
2006
Data mining
I regularly use a biplot or principal components plot as an initial exploratory tool for microarray analyses, but I have not found a good package that does this for me…
Jan 24, 2006
Steve Simon

 

Machine Learning tools in R

*Blog post
2006
Data science
R software
There are a variety of different models that perform supervised learning or classification problems
Jan 24, 2006
Steve Simon

 

Randomization tests for paired data

*Blog post
2006
Unusual data
The randomization test offers a lot of flexibility for analyzing data in ways well beyond what traditional tests might offer. The concept is quite simple. Suppose that you…
Jan 24, 2006
Steve Simon

 

Multicollinearity is not a violation of assumptions

*Blog post
2006
Modeling issues
A colleague from my days at the National Institute for Occupational Safety and Health emailed me a question. Apparently, one of the co-authors of a paper he is writing is in…
Jan 20, 2006
Steve Simon

 

Davis Balestracci seminar

*Blog post
2006
Quality control
A couple of people I work with are very interested in applying quality control in various processes at Children’s Mercy Hospital. We already have a quality improvement…
Jan 19, 2006
Steve Simon

 

Excluding zip codes with insufficient data

*Blog post
2006
Descriptive statistics
Someone asked about a study evaluating rates of children with tooth decay according to the zip code they live in. Some zip codes might have hundreds of children evaluated…
Jan 19, 2006
Steve Simon

 

Categorizing my weblog entries

*Blog post
2006
Website details
It’s probably a sign of lack of discipline on my part, but this research methodology weblog seems to cover just about anything and everything. To help people sort through…
Jan 18, 2006
Steve Simon

 

The Journal of Statistical Software

*Blog post
2006
Statistical computing
The January 2006 issue of Amstat News had the following announcement:
Jan 18, 2006
Steve Simon

 

Characterizing reasons for refusal

*Blog post
2006
Exclusions in research
A participant in the IRB Forum raised a question about a research study where people were asked to participate, and when some of them said “no” they were then asked why they…
Jan 17, 2006
Steve Simon

 

Handling dropouts in NNT/NNH calculations

*Blog post
2006
Measuring benefit and risk
Someone asked a question on the Evidence-Based Health email discussion group about how to handle dropouts in an NNT/NNH calculation. There is no standard way of handling…
Jan 16, 2006
Steve Simon

 

First peek at the cover of my new book

*Blog post
2006
Statistical evidence
Oxford University Press (OUP) just sent me the first draft of the jacket and cover of the book I am writing, Statistical Evidence in Medical Trials.
Jan 12, 2006
Steve Simon

 

Where to go, where to go

*Blog post
2006
Professional details
There are several interesting research conferences this year, and I have to decide quickly which one(s) to attend.
Jan 11, 2006
Steve Simon

 

Extreme value distribution

*Blog post
2006
Probability concepts
I got an interesting question about an application in information theory of a statistical distribution called the Type I extreme value distribution. This distribution, also…
Jan 9, 2006
Steve Simon

 

An entry in Chance News

*Blog post
2006
Wiki pages
For time to time, I have contributed small items to a web publication called Chance News.
Jan 5, 2006
Steve Simon

 

The past year in my weblog

*Blog post
2006
Website details
I just cleaned up the weblog and put all the old entries in separate files in the archive. It was a busy year (though I did slow down a lot in November and December). There…
Jan 4, 2006
Steve Simon

 

Vote for me

*Blog post
2005
Being updated
Professional details
I am running for an elected office, the Vice-Chair of District 4, Region 2, of the Council of Chapters for the American Statistical Association. I could make some jokes…
Dec 21, 2005
Steve Simon

 

Object oriented features of R

*Blog post
2005
Being updated
R software
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 19, 2005
Steve Simon

 

Confidence intervals are needed to evaluate clinical importance

*Blog post
2005
Clinical importance
Back in March, I sent a letter to the American Journal of Psychiatry complaining about their failure to include confidence intervals in their published reports. The journal…
Dec 15, 2005
Steve Simon

 

Fractions are funny

*Blog post
2005
Being updated
Measuring benefit and risk
On my web page about odds ratios, I point out the fractions are funny and cite some well known examples of how fractions behave in a counter intuitive fashion. One of the…
Dec 13, 2005
Steve Simon

 

Group Sequential Monitoring of Clinical Trials in R

*Blog post
2005
Being updated
Early stopping
R software
It is very expensive to purchase software that performs group sequential monitoring of clinical trials (sometimes called interim analysis). Group sequential monitoring is…
Dec 13, 2005
Steve Simon

 

The HapMap project

*Blog post
2005
Being updated
Information theory
One of the research projects I am involved with may make use of the HapMap project (www.hapmap.org). This project is an ambitious effort to document the frequency of most…
Dec 12, 2005
Steve Simon

 

Withholding information

*Blog post
2005
Being updated
Blinding in research
A recent query on the IRB Forum asked about a pilot study. The goal of the pilot study was to see if different ways of presenting the materials would lead to an improvement…
Nov 28, 2005
Steve Simon

 

Hard learned lessons

*Blog post
2005
Being updated
Data management
It’s been a busy month, as noted below, and in a rush to complete all my projects, I ended up doing some things that may have caused a few problems (nothing permanent, of…
Nov 25, 2005
Steve Simon

 

Slow progress on my weblog

*Blog post
2005
Being updated
Website details
You may have noticed how few entries there are in the month of November. That’s just a reflection of the extraordinary surge in work here at Children’s Mercy Hospital.…
Nov 25, 2005
Steve Simon

 

Stepwise regression to screen for covariates

*Blog post
2005
Being updated
Covariate adjustment
Someone wrote asking about how best to use stepwise regression in a research problem where there were a lot of potential covariates. A covariate is a variable which may…
Nov 25, 2005
Steve Simon

 

Web page for Fisher’s Exact test

*Blog post
2005
Being updated
Statistical computing
I get lots of simple requests like calculate Fisher’s Exact test for this two by two table, and I am happy to help out, but there are free web pages that perform these…
Nov 17, 2005
Steve Simon

 

Non-destructive data editing

*Blog post
2005
Being updated
Data management
I recently worked on a project looking at patients having two different types of operations, with and without collar sutures. The data set that the researchers sent to me…
Nov 2, 2005
Steve Simon

 

Seventeen years between research and practice

*Blog post
2005
Being updated
Teaching Resources
I attended an excellent talk by one of the nurses at CMH on the problems with implementing quality improvement initiatives in health care. She cited an interesting…
Nov 2, 2005
Steve Simon

 

A nice definition of anecdotal evidence

*Blog post
2005
Critical appraisal
Robert Todd Carroll, author of The Skeptics Dictionary and creator of the website Skepdic.com, mentioned in a recent newsletter that he has updated his definition for anecdot…
Oct 24, 2005
Steve Simon

 

RMA normalization of microarrays

*Blog post
2005
Genomics analysis
If you ask most statisticians if they want raw data or processed data, they will, for the most part, prefer to look at the raw data. There are two reasons for this. First…
Oct 24, 2005
Steve Simon

 

Searching for information about the molasses with milk enema

*Blog post
2005
Being updated
Information searching
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 15, 2005
Steve Simon

 

A totally negative microarray experiment

*Blog post
2005
Genomics analysis
I’ve been cleaning out my old emails and am finding some real gems of good advice. Someone wrote into the Bioconductor email list wondering what to do when the lowest…
Oct 14, 2005
Steve Simon

 

The fate of retracted articles

*Blog post
2005
Being updated
Ethics in research
A member of the Evidence Based Health email discussion group noted an interesting discussion about a recently retracted Cochrane review:
Oct 14, 2005
Steve Simon

 

Two nice R libraries

*Blog post
2005
Being updated
R software
I found a couple of nice libraries in R available from CRAN (Comprehensive R Achive Network). The first, vcd, was recommended by a regular contributor to the epidemio-l…
Oct 14, 2005
Steve Simon

 

A nonspecific diagnostic test

*Blog post
2005
Being updated
Corroborating evidence
Someone posted a note on the IRBFORUM complaining that the IRB was preventing him/her from volunteering for a test. This company has a very promising “non-intrusive…
Oct 13, 2005
Steve Simon

 

Lost page

*Blog post
2005
Being updated
Earlier versions are here and here.
Oct 12, 2005
Steve Simon

 

Discovering gene information using OMIM

*Blog post
2005
Genomics analysis
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 12, 2005
Steve Simon

 

A simple trick in R

*Blog post
2005
Being updated
R software
There may be times when you have a string in R that represents a specific R command. How would you run this command. This was answered recently on the Bioconductor mailing…
Oct 11, 2005
Steve Simon

 

Responding to a critique of meta-analysis

*Blog post
2005
Being updated
Systematic overviews
A contributor to the Evidence-Based Medicine list offered a possible criticism of meta-analysis. The criticism was along the lines of (I am paraphrasing and summarizing):
Oct 10, 2005
Steve Simon

 

Quality control exercises, Part 2

*Blog post
2005
Quality control
I tried a pilot experiment of a quality control exercise. It seemed to go fairly well. The goal of the exercise was to flip a coin from a table onto a target on the floor…
Oct 5, 2005
Steve Simon

 

Sample size for a binomial confidence interval

*Blog post
2005
Being updated
Sample size justification
Someone asked me for some help with a homework question. I hesitate to offer too much advice in these situations because I don’t want to disrupt the teacher’s efforts to get…
Oct 3, 2005
Steve Simon

 

HIPAA and research

*Blog post
2005
Being updated
Privacy in research
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 22, 2005
Steve Simon

 

An error slips through the peer review process

*Blog post
2005
Being updated
Diagnostic testing
A group of residents wanted me to look at an article because they were confused about the calculation of the likelihood ratio. The numbers that they got were quite different…
Sep 19, 2005
Steve Simon

 

All models are

*Quotation
2005
Statistical models
All models are wrong, but some are useful George Box, as quoted in wikiquote.
Sep 15, 2005
Steve Simon

 

Dishonesty in medical research

*Blog post
2005
Being updated
Ethics in research
Roy Poses, a regular contributor to the email discussion group Evidence Based Health wrote a provocative email pointing out the manipulation of research, ghost-writing, and…
Sep 15, 2005
Steve Simon

 

Free statistics software

*Blog post
2005
Being updated
Statistical computing
The number and quality of free statistical software offerings appears to be increasing. Here are two interesting sites that offer good quality software for free.
Sep 15, 2005
Steve Simon

 

Testing for bimodality

*Blog post
2005
R software
Stata software
Testing for bimodality is a rather tricky thing. A recent discussion of tests of bimodality on edstat-l, though, yielded a few promising leads relating to the Dip test.
Sep 15, 2005
Steve Simon

 

Self experimentation

*Blog post
2005
Being updated
Ethics in research
Stephen Dubner and Steven D. Levitt, authors of the hot selling book, Freakonomics: A Rogue Economist Explores the Hidden Side of Everything, have a regular column in the…
Sep 13, 2005
Steve Simon

 

Science mentoring

*Blog post
2005
Being updated
Teaching resources
I received an email notice through the Kansas/Western Missouri chapter of the American Statistical Association about “Meet the Science Mentor Day.” This is a half day…
Sep 12, 2005
Steve Simon

 

Two articles debating equipoise

*Blog post
2005
Being updated
Equipoise in research
A frequent contributor to the IRBForum (HM) mentioned a couple of articles that discuss equipoise and which are well worth discussing in detail.
Sep 9, 2005
Steve Simon

 

From my associations with doctors in controlled trials

*Quotation
2005
Research ethics
...from my associations with doctors in controlled trials I have learned that the better the statistician understands the doctor/patient relationship and the doctor’s very…
Sep 9, 2005
Steve Simon

 

Quality control exercises

*Blog post
2005
Being updated
Quality control
I’ve taught several courses on Quality Control, and the best part is the practice exercises.
Sep 1, 2005
Steve Simon

 

What’s New in SPSS version 14.0

*Blog post
2005
Being updated
SPSS software
I attended a web seminar, What’s New in SPSS version 14.0, taught by Meta Brown, a Senior Systems Engineer with SPSS, Inc. Version 14 will ship in October 2005. The major…
Aug 17, 2005
Steve Simon

 

Another disaster averted

*Blog post
2005
Being updated
Data management
When you are importing a file from one system to another, lots of little things can trip you up. Here’s an example, and it shows a very subtle problem.
Aug 16, 2005
Steve Simon

 

Contacting and working with me

*Blog post
2005
Being updated
Professional details
This page is outdated, but I am keeping it because I am an electronic pack rat.
Aug 15, 2005
Steve Simon

 

Sample size for a binary endpoint

*Blog post
2005
Being updated
Sample size justification
Someone sent me an email asking for the sample size needed to detect a 10% shift in the probability of recurrence of an event after one of two different surgical procedures…
Aug 12, 2005
Steve Simon

 

IRBs and scientific validity

*Blog post
2005
Being updated
Ethics in research
One of the regular posters on the edstat-l mailing list shared a comment that is commonly held among many of the people I have talked to.
Aug 12, 2005
Steve Simon

 

Case cohort design

*Blog post
2005
Observational studies
During a consultation about an NIH research grant, the term “case cohort design” came up. The Case Cohort design is similar to a nest Case Control design, but also has some…
Aug 11, 2005
Steve Simon

 

Dates in Excel and R

*Blog post
2005
Being updated
R software
Every program uses a slightly different method for calculating date values. Excel, for example, counts the number of days since the start of 1900 (January 1, 1900=1) for…
Aug 10, 2005
Steve Simon

 

All scientific work…

*Quotation
2005
Critical appraisal
To be updated
Earlier versions are here and here.
Aug 5, 2005
Steve Simon

 

Reporting of adverse events

*Blog post
2005
Adverse events
To be updated
Earlier versions are here and here.
Aug 5, 2005
Steve Simon

 

Converting an odds ratio to a relative risk

*Blog post
2005
Being updated
Measuring benefit and risk
The odds ratio and the relative risk do not always agree, especially when the baseline risk level in the control group is large. I have a simple Excel spreadsheet that will…
Aug 3, 2005
Steve Simon

 

Effective communication about randomized clinical trials (created 2005-02-22)

*Blog post
2005
Being updated
(To be added)
Aug 2, 2005
Steve Simon

 

Allegations of scientific misconduct (August 1, 2005)

*Blog post
2005
Being updated
(To be added)
Aug 2, 2005
Steve Simon

 

An inefficient approach to randomization (August 10, 2005)

*Blog post
2005
Being updated
(To be added)
Aug 2, 2005
Steve Simon

 

More on the weaknesses of randomized trials (created 2005-02-14)

*Blog post
2005
Being updated
(To be added)
Aug 2, 2005
Steve Simon

 

S-PLUS Clinical Safety Miner (March 10, 2005, Model, Software)

*Blog post
2005
Being updated
(To be added)
Aug 2, 2005
Steve Simon

 

A third search for the evidence

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 2, 2005
Steve Simon

 

Publication in the ChanceWiki

*Blog post
2005
Wiki pages
Chance News has changed recently to a Wiki format.
Aug 2, 2005
Steve Simon

 

Information content of a continuous distribution

*Blog post
2005
Being updated
Information searching
I was browsing through the book
Aug 1, 2005
Steve Simon

 

Overview of evidence-based-medicine

*Blog post
2005
Being updated
Teaching resources
The Archives of Disease in Childhood has a series of articles on evidence-based Medicine.
Jul 29, 2005
Steve Simon

 

Expected value and moments

*Blog post
2005
Being updated
Probability concepts
Someone asked me what a statistical moment is. That’s a rather technical term and is not needed except in rather theoretical and mathematical discussions. But it is still…
Jul 29, 2005
Steve Simon

 

Moving R objects

*Blog post
2005
Being updated
Data management
R software
I regularly work from home on my laptop, and when I need to re-run some analyses in R, I usually just re-create the original data sets. But there are several ways you can…
Jul 28, 2005
Steve Simon

 

Merging in R

*Blog post
2005
Being updated
R software
Rmarkdown code
Merging is tricky in any program, and you have to be sure that you know what you are doing. I have found that keeping an index variable will allow me to backtrack and find…
Jul 26, 2005
Steve Simon

 

Registration of clinical trials

*Blog post
2005
Being updated
Publication bias
International Committee of Medical Journal Editors (ICMJE) has called for a requirement for registration of clinical trials. All clinical trials that start recruiting on or…
Jul 22, 2005
Steve Simon

 

More on regular expressions

*Blog post
2005
Being updated
Data management
As I work more and more with microarrays, the more I realize that having a knowledge of regular expressions will help. For example, I had a comma separated file (.CSV) and…
Jul 21, 2005
Steve Simon

 

Counterpoint on Google Scholar

*Blog post
2005
Being updated
Information searching
A recently published article:
Jul 19, 2005
Steve Simon

 

Very low values from Cronbach’s Alpha

*Blog post
2005
Measuring agreement
Someone came to me with an analysis of a scale of 16 items, where the Cronbach’s alpha computed for that scale was only 0.14. The first thing you should look for in this…
Jul 19, 2005
Steve Simon

 

The difference between absolute risks and relative risks

*Blog post
2005
Measuring benefit and risk
There are two general ways to compare a treatment and a control group, relative comparisons and absolute comparisons. For a relative comparison, the basic computation is…
Jul 15, 2005
Steve Simon

 

Confidence interval for a correlation coefficient

*Blog post
2005
Confidence intervals
Sample size justification
In many exploratory research studies, the goal is to examine associations among multiple demographic variables and some outcome variables. How can you justify the sample…
Jul 11, 2005
Steve Simon

 

What does a 60% drop mean?

*Blog post
2005
Being updated
Measuring benefit and risk
A friend sent me an email quoting the following statistic: “A woman’s chances of getting married dropped 60% for every rise of 15 points in her IQ, according to an English…
Jun 20, 2005
Steve Simon

 

Step-down procedures for multiple comparisons

*Blog post
2005
Being updated
Hypothesis testing
In some research studies, you have a large and difficult to manage set of outcome measures. This is especially true in microarray experiments, where for thousands or tens of…
Jun 16, 2005
Steve Simon

 

Some articles on meta-analysis

*Blog post
2005
Being updated
Systematic overviews
I found a couple of interesting articles on meta-analysis that are difficult to classify:
Jun 10, 2005
Steve Simon

 

More on the retroactive prayer study

*Blog post
2005
Being updated
Corroborating evidence
I discuss an interesting study on the effects of prayer (Leibovici 2001) published in BMJ, where the researcher prayed over a set of charts that represented outcomes…
Jun 10, 2005
Steve Simon

 

I abhor Lilliefor and other tests of normality

*Blog post
2005
Statistical assumptions
Someone asked me about a log transformation for their data. It seemed like a good idea, based on my general comments on the log transformation, but the test of significance…
Jun 7, 2005
Steve Simon

 

Another top ten study in EBM (February 14, 2005)

*Blog post
2005
Being updated
(To be added)
Jun 7, 2005
Steve Simon

 

Ten research studies that anyone teaching EBM should be familiar with (January 17, 2005)

*Blog post
2005
Being updated
(To be added)
Jun 7, 2005
Steve Simon

 

Another search for evidence

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jun 7, 2005
Steve Simon

 

When the F test is significant, but Tukey is not (created 2005-09-09)

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jun 7, 2005
Steve Simon

 

When can I stop my CQI study?

*Blog post
2005
Being updated
Early stopping
I was asked today about a CQI project where children were being tested for a certain condition, but they never tested positive. This was going on for over a year and there…
Jun 6, 2005
Steve Simon

 

Taking charges of conflicting interest too far

*Blog post
2005
Broken link
Conflict of interest
You should always be aware of potential conflicts of interest. Sometimes researchers allow a financial incentive to influence their research and end up skewing the data to…
Jun 4, 2005
Steve Simon

 

The paired availability design

*Blog post
2005
Being updated
Observational studies
In the quest to finish my book on Statistical Evidence, I had to leave some material on the cutting room floor. One of the nicer descriptions was about the paired…
May 31, 2005
Steve Simon

 

Changes to STAT-L/sci.stat.consult

*Blog post
2005
Broken link
Obsolete page
Teaching resources
Note: STAT-L is no longer active. I am keeping this page around for historical reasons.
May 25, 2005
Steve Simon

 

Importing value labels from Access into SPSS

*Blog post
2005
Being updated
Data management
Someone asked about importing data from Access into SPSS. The Access file has value labels (e.g., 1=Male, 2=Female, 3=Missing) and wanted to know if there was any<U+FFFD>…
May 24, 2005
Steve Simon

 

When one group only has a single observation

*Blog post
2005
Being updated
Small sample size issues
Someone asked me about a lab study comparing expression levels for two groups of patients. The first group has two copies of a gene and the second group has three copies of…
May 24, 2005
Steve Simon

 

Another open site closes

*Blog post
2005
Being updated
Writing research papers
I often link to interesting resources on the web, and it is always distressing to find that content which had been available freely is now available only through…
May 23, 2005
Steve Simon

 

Adjusting for covariate imbalance

*Blog post
2005
Being updated
Covariate adjustment
Here’s a graph I want to insert in my book. It illustrates how to adjust for covariate imbalance. The data comes from the Data and Story Library
May 20, 2005
Steve Simon

 

Computing normal probabilities

*Blog post
2005
Being updated
Statistical computing
One of the programs here at Children’s Mercy Hospital is helping me take an Excel spreadsheet and developing a Windows program that will do the same calculations faster and…
May 19, 2005
Steve Simon

 

What is critical thinking?

*Blog post
2005
Being updated
Critical appraisal
A lot of people use the term “critical thinking” in an offhand way. Usually the writer who uses this term is trying to imply that anyone who disagrees with the writer’s…
May 17, 2005
Steve Simon

 

More on searching the literature

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 17, 2005
Steve Simon

 

Geometric distribution

*Blog post
2005
Being updated
Probability concepts
Someone asked me about a game where A, B, and C toss a coin in order (A first, then B, then C, then A again, etc.) until someone gets a heads on their coin flip. What are…
May 16, 2005
Steve Simon

 

You have to make a distinction between the science and the technological applications

*Quotation
2005
Theory versus practice
Earlier versions are here and here.
May 16, 2005
Steve Simon

 

Hedge’s G

*Blog post
2005
Being updated
Systematic overviews
Someone asked me today about Hedge’s G. I had never heard of it before, but if you do a web search, you will find
May 13, 2005
Steve Simon

 

Post hoc power is never justified

*Blog post
2005
Being updated
Post hoc power
Someone wrote in and was upset that a referee was insisting on post hoc power for all the outcome measures, and he only wanted to compute post hoc power for the negative…
May 13, 2005
Steve Simon

 

Confidence intervals around a safety level

*Blog post
2005
Being updated
Confidence intervals
Someone asked me about an environmental clean up. The government told them that the location was cleaned up to a 90% confidence level of the standard. Would this give the…
May 11, 2005
Steve Simon

 

String manipulations in R

*Blog post
2005
Being updated
Data management
R software
As part of my efforts to analyze microarray data, I am finding that I need to do simple string manipulations in R. Here is a list of functions that might help.
May 10, 2005
Steve Simon

 

Preserving spacing in html code

*Blog post
2005
Being updated
Website details
Note that this page is obsolete (I am writing this note on 2020-10-26). I am currently transitioning to using Markdown and RMarkdown for my website.
May 6, 2005
Steve Simon

 

Searching the literature

*Blog post
2005
Being updated
Information searching
Next week, our hospital will have a seminar on Reiki. I thought it would be useful to see what evidence there was on this technique. My search included access to several…
May 3, 2005
Steve Simon

 

Meta-analysis talk

*Blog post
2005
Being updated
Systematic overviews
Today I gave a talk on meta-analysis. I started with a general overview of meta-analysis, and then discussed some of the particular problems associated with a meta-analysis…
May 2, 2005
Steve Simon

 

PubMed tags

*Blog post
2005
Being updated
Information searching
Searching in PubMed can be tricky. If you don’t find what you want the first time, it may help to specify exactly what part of the PubMed record you want to search for.
Apr 28, 2005
Steve Simon

 

Determining the optimal threshold for a diagnostic test

*Blog post
2005
Being updated
Diagnostic tests
Someone asked me about how to design an experiment that would use the ROC curve to determine an appropriate threshold for a diagnostic test.
Apr 27, 2005
Steve Simon

Searching the Internet

*Blog post
2005
Being updated
Information searching
A response to a question on the stat-l discussion group provided a clever way of searching the Internet. Someone asked about finding references about how to analyze ordinal…
Apr 26, 2005
Steve Simon

 

MedStats discussion group

*Blog post
2005
Being updated
Teaching resources
If you don’t get enough email already, a new discussion group, MedStats, was created recently. MedStats is hosted on Google Groups. The main page for MedStats is groups.googl…
Apr 25, 2005
Steve Simon

 

More than 90% censored values

*Blog post
2005
Survival analysis
Someone asked me about running a Cox proportional hazards regression model when over 90% of the observations were censored. That means (if the outcome of interest was…
Apr 22, 2005
Steve Simon

 

The test of a first rate intelligence

*Quotation
2005
Human side of Statistics
The test of a first rate intelligence is the ability to hold two opposed ideas in the mind at the same time and still retain the ability to function. F Scott Fitzgerald…
Apr 20, 2005
Steve Simon

Measuring agreement

*Blog post
2005
Being updated
Measuring agreement
Someone reviewing a paper asked me about all the “weird statistics” being used in the paper, such as the Bland-Altman plot and Deming regression.
Apr 19, 2005
Steve Simon

 

Incidence density ratio

*Blog post
2005
Being updated
Measuring benefit and risk
Someone asked me about a technical term, incidence density ratio, that was used in an article:
Apr 19, 2005
Steve Simon

 

S-plus version 7

*Blog post
2005
Being updated
Statistical computing
I attended a web seminar by David Smith introducing the latest version of S-plus, version 7.This software, produced by Insightful Corporation, is one of my favorite products…
Apr 19, 2005
Steve Simon

 

Profile analysis and MANOVA

*Blog post
2005
Being updated
Multilevel models
Someone asked me about profile analysis as alternative analysis to MANOVA (Multivariate Analysis of Variance). Typically you would use profile analysis when the outcome…
Apr 18, 2005
Steve Simon

 

Fair Use of copyrighted material

*Blog post
2005
Being updated
Website details
I get many requests to link to my web pages, and I always grant these requests. Other people ask if they can use portions of my material on their web pages or in their…
Apr 15, 2005
Steve Simon

 

Presenting Numbers, Tables, and Charts

*Blog post
2005
Being updated
Descriptive statistics
I got a nice email from Sally Bigwood, one of the coauthors of
Apr 15, 2005
Steve Simon

 

Tolerance limits

*Blog post
2005
Being updated
Quality control
Someone asked me about the difference between control limits and tolerance limits.
Apr 15, 2005
Steve Simon

 

Do I have enough data after 24 months of time?

*Blog post
2005
Being updated
Clinical importance
Early stopping
Someone asked me about a correlation coefficient that he computed on a data set that represented 24 months of data collection. A particular correlation of interest (a…
Apr 5, 2005
Steve Simon

 

Summing ordinal data

*Blog post
2005
Being updated
Descriptive statistics
You have a questionnaire which asks several related questions on a Likert scale (1=Strongly Disagree, 2=Disagree, etc.). You want to add these items together and then report…
Apr 5, 2005
Steve Simon

 

Where is the confidence interval?

*Blog post
2005
Being updated
Clinical importance
Confidence intervals
A recent letter to the editor,
Mar 31, 2005
Steve Simon

 

Non-random samples

*Blog post
2005
Being updated
Observational studies
Someone sent me an email asking about a project that involved interviews of women at higher levels of management in an organization. This is a rather small group, and might…
Mar 25, 2005
Steve Simon

 

Open-ended questions on a survey

*Blog post
2005
Survey design
No one seems to talk about how to handle those pesky open-ended questions you see on a survey. I usually hold my breath and hope that the researcher doesn’t think to mention…
Mar 25, 2005
Steve Simon

 

Inferential and descriptive statistics

*Blog post
2005
Being updated
Descriptive statistics
Someone asked me whether it was okay to define a correlation coefficient as a descriptive statistic. It depends on whether the correlation is being used to describe a…
Mar 24, 2005
Steve Simon

 

More on information theory models

*Blog post
2005
Being updated
Information theory
Some of the people I work with have used information theory extensively in their work. A good summary of their efforts appears in
Mar 24, 2005
Steve Simon

 

Surrogate outcomes

*Blog post
2005
Being updated
I’m on the mailing list of the Alliance for Human Research Protection, and they highlighted a book review:
Mar 23, 2005
Steve Simon

 

A collection of randomized and non-randomized studies

*Blog post
2005
Being updated
Observational studies
Randomization
I’m updating some of my training classes to use examples from open source journals, because it is easier for me to include content of these articles directly in the web pages.
Mar 22, 2005
Steve Simon

 

Coming soon!

*Blog post
2005
Being updated
Website details
Under the details section of these web pages, I have a page talking about future plans. After months of neglect, I took the time to update that page. I also need to keep…
Mar 22, 2005
Steve Simon

 

Meta-analysis for a diagnostic test

*Blog post
2005
Being updated
Systematic overviews
What I originally wrote for this page has been replaced by
Mar 22, 2005
Steve Simon

 

Language resources

*Blog post
2005
Being updated
Information searching
Once in a while, I will get an email or find a website written in a foreign language. The best way to handle this is through BabelFish:
Mar 22, 2005
Steve Simon

 

Using Mathematica and Matlab for Statistics

*Blog post
2005
Being updated
Statistical computing
Mathematica, produced by Wolfram Research, is a program which performs numeric and symbolic computations. It also can produced sophisticated graphical images. There are two…
Mar 22, 2005
Steve Simon

 

Stratified Cox regression models

*Blog post
2005
Being updated
Survival analysis
Someone sent me an email asking about a Cox regression model that included a strata for clinics. What’s the best way to handle strata? That’s a tricky question to answer.…
Mar 22, 2005
Steve Simon

 

Meta-analysis

*Blog post
2005
Being updated
Systematic overviews
Meta-analysis is the quantitative combination of results from multiple research studies. There are three steps in a typical meta-analysis model.
Mar 18, 2005
Steve Simon

 

Digitizing a graph

*Blog post
2005
Being updated
Data management
Someone brought me a graph with a trend line relating body surface area (BSA) to various cardiac measurements. This graph showed both the trend line and limits at +/-2…
Mar 15, 2005
Steve Simon

 

Quality of published research

*Blog post
2005
Being updated
Systematic overviews
One of the big advantages of meta-analysis is that it allows you to review a series of publications in an area to see if there are any gaps or quality shortfalls. While I…
Mar 14, 2005
Steve Simon

 

Publicon software

*Blog post
2005
Being updated
Statistical computing
Wolfram Research, makers of the famous software for symbolic mathematical calculations, Mathematica, have released a new product for technical publications, Publicon.…
Mar 14, 2005
Steve Simon

 

Selective reporting of research findings

*Blog post
2005
Being updated
Publication bias
I have talked extensively about publication bias in my weblog
Mar 14, 2005
Steve Simon

 

Clinical importance

*Blog post
2005
Being updated
Clinical importance
Many journal authors have the bad habit of looking just at the p-value of a study and ignoring the clinical importance of their findings. If they get a small p-value, which…
Mar 11, 2005
Steve Simon

 

Cumulative meta-analysis

*Blog post
2005
Being updated
Systematic overviews
This figure below, published in
Mar 11, 2005
Steve Simon

 

Analysis of subgroup results

*Quotation
2005
Multiple comparisons
Analysis of subgroup results in a clinical trial is surprisingly unreliable, even in a large trial. This is the result of a combination of reduced statistical power…
Mar 10, 2005
Steve Simon

 

Lost page

*Blog post
2005
Being updated
Earlier versions are here and here.
Mar 10, 2005
Steve Simon

 

It seems to me reasonable to look for benefit or harm

*Quotation
2005
Subgroup analysis
It seems to me reasonable to look for evidence of benefit or harm in certain biologically plausible subgroups, even though the statistical basis for this evidence is not…
Mar 10, 2005
Steve Simon

 

Technology to end spam

*Blog post
2005
Being updated
Bayesian statistics
In my job I get a lot of spam, partly because I listed my email address on my web site until just recently. The research community is trying to find technological solutions…
Mar 8, 2005
Steve Simon

 

Sample size calculation for a nonparametric test

*Blog post
2005
Being updated
Sample size justification
I got an email inquiry about how to calculate power for a Wilcoxon signed ranks test. I don’t have a perfect reference for this, but I do have a brief discussion on sample…
Mar 8, 2005
Steve Simon

 

PowerPoint Counterpoint

*Blog post
2005
Being updated
Presenting research
I am a rather harsh critic of PowerPoint,
Mar 2, 2005
Steve Simon

 

The costs of a false positive test

*Blog post
2005
Being updated
Diagnostic testing
The New York Times had an excellent article on newborn screening tests.
Mar 1, 2005
Steve Simon

 

Growth curves

*Blog post
2005
Being updated
Nonlinear regression
The New York Times has a nice article about Dr. James Tanner, an expert on childhood growth.
Mar 1, 2005
Steve Simon

 

Adjusting for a baseline measurement

*Blog post
2005
Broken link
Covariate adjustment
Someone asked me today about how to analyze a two group experiment with a baseline value. This is common research design. Researchers will assess all patients at the…
Feb 28, 2005
Steve Simon

 

More on the top ten studies in EBM

*Blog post
2005
Being updated
Teaching resources
I may never get this paper done, but the effort is still worthwhile in that I am learning a lot. I rediscovered a wonderful web page developed by Ben Djulbegovic, Randomized…
Feb 28, 2005
Steve Simon

 

Taguchi methods

*Blog post
2005
Being updated
Quality control
Genichi Taguchi was a Japanese engineer and statistician who developed a wide range of statistical tools for improving the quality of industrial manufacturing. These tools…
Feb 22, 2005
Steve Simon

 

Sackettisation, the artificial linkage

*Quotation
2005
Evidence Based Medicine
Sackettisation ... the artificial linkage of a publication to the evidence-based medicine movement in order to improve sales. bmj.bmjjournals.com/cgi/content/full/320/7244/12…
Feb 21, 2005
Steve Simon

 

Scientific papers serve the needs of their authors

*Quotation
2005
Writing research papers
...scientific papers serve the needs of their authors above those of their readers. Why else would a journal devote five pages to a paper that reached this conclusion? “In…
Feb 21, 2005
Steve Simon

 

Security tends to be

*Quotation
2005
Being updated
Incomplete page
Privacy in research
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Feb 21, 2005
Steve Simon

 

Developing good practice guidelines

*Blog post
2005
Being updated
Teaching Resources
A physician here, Lloyd Olson, who has been aggressively promoting Evidence Based Medicine suggested the following interesting article on practice guidelines.<U+FFFD>
Feb 18, 2005
Steve Simon

 

Report cards

*Blog post
2005
Being updated
Evidence Based Medicine
Teaching resources
The Minnesota Department of Health recently published a report over a 15 month period that documenting 99 events occurring in Minnesota hospitals that should never occur.…
Feb 16, 2005
Steve Simon

 

Side effects of Cox-2 inhibitors

*Blog post
2005
Being updated
Measuring benefit and risk
There has been so much published about side effects of Cox-2 inhibitors that it is hard to keep up with the evolving story. Here are a few recently released articles:
Feb 15, 2005
Steve Simon

 

Moderator variables

*Blog post
2005
Being updated
Covariate adjustment
I’ve always disliked the excessive use of detailed terminology, but when someone asked me about moderator variables, I had to look up the details. Basically, a moderator…
Feb 15, 2005
Steve Simon

 

Public access to publications from NIH-funded research

*Blog post
2005
Being updated
Writing research papers
The NIH is now requesting publication in PubMed Central of research publications that is supported in whole or in part by NIH grants. The authors can designate a time delay…
Feb 15, 2005
Steve Simon

 

Optimization using the MM algorithm

*Blog post
2005
Being updated
Statistical computing
A comment on EDSTAT-L reminded me about this important issue. Many problems in Statistics involve finding an optimal point of a rather complex and messy function. In some…
Feb 14, 2005
Steve Simon

 

Relationship between sample size and p-values

*Blog post
2005
Being updated
Pvalues
I got a rather basic inquiry about p-values, but it is worth mentioning. Someone had a data set with 9,000 observations and was unhappy with the p-value that he got in a…
Feb 14, 2005
Steve Simon

 

Control charts for monitoring mortality rates

*Blog post
2005
Being updated
Adverse events
One of the trickiest problems in Medicine is trying to identify whether an unusual trend in mortality rates is an indication of an incompetent physician, or worse, a…
Feb 11, 2005
Steve Simon

 

Continuous variables in a logistic regression model

*Blog post
2005
Being updated
Logistic regression
I got a question by email that asked, in a rather indirect way, how to interpret the odds ratio estimate for a continuous variable in a logistic regression model. It turns…
Feb 9, 2005
Steve Simon

 

A small p-value does not mean a large difference

*Blog post
2005
Being updated
Pvalues
Someone asked me if the p-value for a t-test indicates the size of the difference between two groups. It turns out that the p-value is related both to the size of the…
Feb 8, 2005
Steve Simon

 

Sampling the entire population

*Blog post
2005
Being updated
Descriptive statistics
A commonly occurring question is what to do when you have a small population that you are sampling and your sample effectively constitutes all or almost all of the…
Feb 3, 2005
Steve Simon

 

A surprising application of the harmonic mean

*Blog post
2005
Being updated
Statistical theory
The radio show, Car Talk, has a puzzle that they read every week on the show. Usually, it is some unusual or unexpected problems with automobiles, but Ray and Tom Magliozzi…
Feb 1, 2005
Steve Simon

 

Statistical Evidence in Medical Trials

*Blog post
2008
Being updated
Statistical evidence book
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 27, 2005
Steve Simon

 

Placing consecutive dates in a column of an SPSS file

*Blog post
2005
SPSS software
Someone gave me a data set with 549 rows of data. The first row corresponded to observations on 06/01/2003, the second to 06/02/2003, and so forth through 11/30/2004. She…
Jan 26, 2005
Steve Simon

 

Re-weighting the data

*Blog post
2005
Being updated
Covariate adjustment
A recent article
Jan 25, 2005
Steve Simon

 

A mathematician is

*Quotation
2005
Mathematics
A mathematician is a machine for turning coffee into theorems. Paul Erdos. It’s worth noting that Paul Erdos is one of the most eccentric mathematicians, a group that…
Jan 24, 2005
Steve Simon

 

Steps in a typical Bayesian model

*Blog post
2005
Bayesian statistics
I . “Should proponents of EBM be concerned about understanding the Bayesian philosophy? In my opinion, no. I think we’ll gradually see Bayesian philosophy creep in to the…
Jan 24, 2005
Steve Simon

 

No human investigation can be called real science

*Quotation
2005
Mathematics
No human investigation can be called real science if it cannot be demonstrated mathematically. Leonardo da Vinci
Jan 24, 2005
Steve Simon

 

Steps in a typical Bayesian model

*Blog post
1999
Being updated
Bayesian statistics
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 24, 2005
Steve Simon

 

Twas the night before surgery

*Quotation
2005
Ethics in research
A Visit to the ER from St. Nick
Jan 24, 2005
Steve Simon

 

What do you call the removal of

*Quotation
2005
Privacy in research
Q. What do you call the the removal of individually identifiable health information from health records? A. HIPAAectomy. Found at www.hipaadvisory.com/live/FAQ/humor.htm. No…
Jan 24, 2005
Steve Simon

 

How good is your intuition?

*Blog post
2005
Being updated
Critical appraisal
One definition of Evidence Based Medicine is
Jan 21, 2005
Steve Simon

 

Summary Receiver Operating Characteristic Curve

*Blog post
2005
Being updated
Systematic overviews
In the past week, I have had two inquiries about how to perform a meta-analysis of studies of a diagnostic test. An intriguing idea that I discovered in researching this is…
Jan 21, 2005
Steve Simon

 

Adjusted odds ratios

*Blog post
2005
Covariate adjustment
Someone asked me today how to compute an adjusted odds ratio. He has a case control study where cases represent cancer patients. He also has various Single Nucleotide…
Jan 20, 2005
Steve Simon

 

Testing baseline imbalance in a randomized study

*Blog post
2005
Covariate adjustment
Randomization will roughly balance out the covariates between the treatment group and the control group because of the law of large numbers. Once in a while, though, an…
Jan 19, 2005
Steve Simon

 

The Digital Object Identifier

*Blog post
2005
Being updated
Information searching
Many journals are now using the Digital Object Identifier (DOI) to reference their publications.
Jan 19, 2005
Steve Simon

 

Confusion about p-values

*Blog post
2005
Hypothesis testing
Someone wrote to me with a statement that represents a commonly held, but false belief. He stated, in effect, that a p-value of 0.06 means that there is only a 6%…
Jan 18, 2005
Steve Simon

 

More thoughts on equipoise

*Blog post
2005
Being updated
Equipoise in research
Vital to the ethical conduct of a clinical trial is the concept of equipoise, that a researcher is clinically indifferent or genuinely uncertain, as to whether a new therapy…
Jan 17, 2005
Steve Simon

 

Small relative risks

*Blog post
2005
Being updated
Measuring benefit and risk
I found a quote on the Skeptic’s Dictionary web site that is worth commenting on. The author, Robert Todd Carroll was describing the Vioxx controversy and the lawyers who…
Jan 13, 2005
Steve Simon

 

Forest plots

*Blog post
2005
Being updated
Systematic overviews
Many meta-analyses use a graph known as a forest plot. I was always confused by the funny squares in a forest plot, so I looked for a description. An example of a forest…
Jan 12, 2005
Steve Simon

 

Two cautionary tales about data mining

*Blog post
2005
Data mining
I attended a 7am seminar this morning on data warehousing and data mining, which was quite good. It reminded me of a couple of stories I heard about the pitfalls of data…
Jan 6, 2005
Steve Simon

 

Odds ratios less than one

*Blog post
2005
Being updated
Measuring benefit and risk
Someone sent me an email asking how to interpret an odds ratio less than 1. An odds ratio of 1 means that the odds of an event is the same in both the treatment and control…
Jan 6, 2005
Steve Simon

 

Spectrum Bias

*Blog post
2005
Being updated
Diagnostic testing
Observational studies
I tried to start a page on diagnostic tests a while back, but have not had the time to fully develop it. One of the important issues for diagnostic tests is spectrum bias.
Jan 4, 2005
Steve Simon

 

Monetary incentives

*Blog post
2005
Being updated
Ethics in research
Someone on the IRBForum asked about monetary incentives in research. This is a controversial area (see the OHRP website, Foy 1998, Sugarman 2004, Young 2001), and especially…
Jan 3, 2005
Steve Simon

 

Best EBM methods or teaching papers in 2004

*Blog post
2005
Evidence Based Medicine
Paul Glasziou compiled a list for the best EBM papers in 2004. These papers had to deal with either methods for EBM or teaching of EBM. Here is the list:
Jan 1, 2005
Steve Simon

 

More on conflicts of interest

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Examples of confidence intervals

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

What alternative medicine can teach us about evidence-based medicine

*Blog post
2005
Being updated
(To be added)
Jan 1, 2005
Steve Simon

 

Ethical principles for Complementary and Alternative Medicine

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

The ethics of randomization

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

A controversial meta-analysis

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Media interview tips

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Statistical Analysis of Microarrays by Insightful Software

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

The S+ CorrelatedData Library (May 19, 2005)

*Blog post
2005
Being updated
Multilevel models
Obsolete page
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Standard deviation versus standard error (May 16, 2005)

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Two articles in the Chance Wiki

*Blog post
2005
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2005
Steve Simon

 

Testing for side effects

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 29, 2004
Steve Simon

 

Weblinks for December 2004

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 28, 2004
Steve Simon

 

Zhenya

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 24, 2004
Steve Simon

 

Designing a questionnaire

*Blog post
2004
Survey design
I’m behind in my reading of the British Medical Journal, and the first issue I looked at today has a gem of an article.
Dec 24, 2004
Steve Simon

 

Is the randomized trial the gold standard for research?

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 24, 2004
Steve Simon

 

Can you recommend a good book?

*Blog post
2004
Teaching resources
Being updated
(To be added)
Dec 24, 2004
Steve Simon

 

Outcomes research

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 24, 2004
Steve Simon

 

Design and analysis of pilot studies

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 24, 2004
Steve Simon

 

Zhenya

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 24, 2004
Steve Simon

 

Simpson’s Paradox

*Blog post
2004
Statistical theory
Someone wrote to the Evidence Based Health email discussion group about a theoretical situation where someone had an estimated risk of disease based on a study that showed…
Dec 22, 2004
Steve Simon

 

Subgroup analysis

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 21, 2004
Steve Simon

 

Hiring a statistician after the data has been collected

*Quotation
2004
Human side of Statistics
“Hiring a statistician after the data has been collected is like hiring a physician when your patient is in the morgue. He might be able to tell you what went wrong, but he…
Dec 20, 2004
Steve Simon

 

Neyman bias

*Blog post
2004
Measuring benefit and risk
Selection of controls in a case-control study is difficult enough, but you also have to worry about the selection of the cases. Do you select incident cases (for example all…
Dec 15, 2004
Steve Simon

 

Prayer studies

*Blog post
2004
Corroborating evidence
I’ve been meaning to write a web page about the series of studies that seem to indicate that groups of patients receiving prayer get better health outcomes than the control…
Dec 13, 2004
Steve Simon

 

New in SPSS version 13.0

*Blog post
2004
SPSS software
I attended a web seminar on the new enhancements in version 13.0 of SPSS software. The most notable change is in date calculations.
Dec 7, 2004
Steve Simon

 

Entrenched beliefs

*Blog post
2004
Critical appraisal
A member of the Evidence Based Health listserv wrote about a workshop he taught on Evidence Based Medicine (EBM). It went pretty well, he thought until he overheard a…
Dec 1, 2004
Steve Simon

 

Confidence intervals

*Blog post
2003
Being updated
Can you give me a simple explanation of what a confidence interval is?
Nov 29, 2004
Steve Simon

 

Measuring heterogeneity in meta-analysis

*Blog post
2004
Systematic overviews
While browsing through the archives of the British Medical Journal, I noticed an excellent article on measuring heterogeneity in meta-analysis. There is a new measure…
Nov 29, 2004
Steve Simon

 

Lost page

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 29, 2004
Steve Simon

 

Controversy over stopping a study early

*Blog post
2004
Early stopping
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 24, 2004
Steve Simon

 

Alternatives to equipoise

*Blog post
2004
Equipoise in research
Stephen Senn wrote an interesting article a couple of years ago that provides an intriguing alternative to the concept of equipoise. I wrote about equipoise in a web page…
Nov 24, 2004
Steve Simon

 

Intellectual conflict of interest

*Recommendation
2004
Conflict of interest
Jeanne Lenzer. FDA bars own expert from evaluating risks of painkillers. BMJ 2004-11-18; 329: 1203. doi:10.1136/bmj.329.7476.1203. This article is behind a paywall.
Nov 24, 2004
Steve Simon

 

Unequal sample sizes

*Blog post
2004
Sample size justification
For some reasons, it seems to unnerve people when the sample size in the treatment and control group are not the same. They worry about whether the tests that they would run…
Nov 24, 2004
Steve Simon

 

Software patents

*Blog post
2004
Statistical computing
I have always found the concept of software patents confusing. I am listed as a co-inventor on a software patent, so perhaps that raises a conflict of interest. Still, here…
Nov 19, 2004
Steve Simon

 

Ratio of observations to independent variables

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Nov 17, 2004
Steve Simon

 

Discrepancy between univariate and multivariate models

*Blog post
2004
Modeling issues
Someone asked me about an analysis that showed certain factors were predictive of a health outcome when considered individually. When these factors were included in a…
Nov 12, 2004
Steve Simon

 

Testing multinomial proportions

*Blog post
2004
Probability concepts
I received an email inquiry about a problem that seems simple enough, but which just doesn’t seem to have an easy answer. This person gave the following hypothetical data.
Nov 9, 2004
Steve Simon

 

Confidence intervals for complex research designs

*Blog post
2004
Sample size justification
Someone asked me by email about confidence intervals in complex research designs. This person had rejected the use of post hoc power calculations, and wanted instead to use…
Nov 5, 2004
Steve Simon

 

Research on therapies that have no known mechanism of action

*Blog post
2004
Corroborating evidence
Several people on the IRBForum have made comments along the lines that research on certain alternative medicines (such as homeopathy) has no scientific merit because there…
Nov 4, 2004
Steve Simon

 

Anecdotal information

*Blog post
2004
Critical appraisal
Anecdotal information is problematic for several reasons, and I have highlighted some of these reasons in a speech I gave at the 2004 meeting of the Midwest Society for…
Nov 2, 2004
Steve Simon

 

Unblinding at the end of a study

*Blog post
2004
Blinding in research
When a study a placebo controlled study is completed, patients in both arms of the study are often offered the active drug at the end of the study at no cost as a way of…
Nov 1, 2004
Steve Simon

 

Automating statistical analyses

*Blog post
2004
Statistical computing
Many of my projects involve writing a program in my text editor (Textpad), copying it into the clipboard, and then pasting it into a statistical program like S-plus or Stata.…
Oct 25, 2004
Steve Simon

 

Unnecessary diagnostic tests

*Blog post
2004
Diagnostic testing
You would think that you can never have enough information about your health. Barring financial considerations, the more testing the better.
Oct 25, 2004
Steve Simon

 

Top six mistakes in teaching EBM

*Blog post
2004
Teaching Resources
I attended a lunch roundtable session on the role of statisticians in teaching Evidence-Based practice to future clinicians. I didn’t get a chance to write up a summary of…
Sep 24, 2004
Steve Simon

 

The price of Kaplan-Meier

*Blog post
2004
Survival analysis
I rarely find time to read the Statistics journals anymore, but I did run across an excellent article in the September 2004 issue of JASA.
Sep 23, 2004
Steve Simon

 

Multiple degree of freedom tests

*Blog post
2004
Analysis of variance
Someone sent me an email describing a situation where an interaction effect in SPSS had a large p-value, but one of the individual components of that interaction had a small…
Sep 22, 2004
Steve Simon

 

Sample size for an ordinal outcome

*Blog post
2004
Sample size justification
Someone asked me for some help with calculating an appropriate sample size for a study comparing two treatments, where the outcome measure is ordinal (degree of skin…
Sep 22, 2004
Steve Simon

 

A simple microarray experiment

*Blog post
2004
Data mining
Someone just gave me some data with a small microarray. There are four exposed animals (Exp.1 through Exp.4) and four control animals (Exp.5 through Exp.8). The microarray…
Sep 21, 2004
Steve Simon

 

What’s the best statistical model?

*Blog post
2004
Modeling issues
Someone asked me by email about the advantages and disadvantages of various statistical models (multinomial logistic regression, ordinal logistic regression, and structural…
Sep 17, 2004
Steve Simon

 

Rates versus proportions

*Blog post
2004
Confidence intervals
Many people use the words “rates” and “proportions” interchangeably, but there is an important distinction that I draw.
Sep 15, 2004
Steve Simon

 

Printer friendly versions of web pages

*Blog post
2004
Website details
I use Microsoft FrontPage, and their newsletter listed a resources for creating printer friendly web pages. I dislike the idea of having a separate set of pages for…
Sep 13, 2004
Steve Simon

 

International Classification of Functioning, Disability, and Health

*Blog post
2004
Teaching resources
Donald Lollar presented a seminar: “The International Classification of Functioning, Disability, and Health (ICF).” The ICF is a framework for classifying health status that…
Sep 10, 2004
Steve Simon

 

Full-Body Computed Tomography Screening

*Blog post
2004
Diagnostic testing
Full body scans represent a good example of the conflicting considerations when you need to evaluate a screening test. A full body scan uses a CT (Computerized Tomography)…
Sep 6, 2004
Steve Simon

 

Nitty Gritty NIH

*Blog post
2004
Grant writing
Bill Caskey talked about some of the nitty gritty details of the NIH Grant process. His talk focused mostly on what happens after a grant gets funded.
Sep 3, 2004
Steve Simon

 

More on information theory models

*Blog post
2004
Information theory
I received a few suggestions for interesting web sites today. They deal with information theory and trying to establish causation.
Aug 31, 2004
Steve Simon

 

Report cards

*Blog post
2004
Unusual data
I’m working on a project looking at some outcomes that might eventually become part of a report card or benchmarking system. This is an area fraught with controversy and it…
Aug 27, 2004
Steve Simon

 

Statistical software

*Blog post
2004
Statistical computing
Back when I was writing the FAQ (Frequently Asked Questions) for stat-l/sci.stat.consult, I had a question about how to contact commercial statistical software vendors and wh…
Aug 25, 2004
Steve Simon

 

Free Full Text on the Web

*Blog post
2004
Writing research papers
As I mention at the top of the weblog, I preferentially try to cite medical literature where there is free full text available on the web. There are several journals who…
Aug 24, 2004
Steve Simon

 

Selection bias

*Blog post
2004
Exclusions in research
The CarTalk radio show has an interesting puzzle every week and often these puzzles involve mathematics. These puzzles can sometimes help you understand complex mathematical…
Aug 24, 2004
Steve Simon

 

Stratified randomization

*Blog post
2004
Randomization
A writer on the IRB Discussion Forum asked a question about how to explain stratified randomization in an informed consent document.
Aug 24, 2004
Steve Simon

 

Unbalanced sample sizes for evaluating a diagnostic test

*Blog post
2004
Diagnostic testing
I get a lot of questions about unbalanced sample sizes. Quite often the mechanics of the research protocol make it easier to find a lot of patients in one group and only a…
Aug 5, 2004
Steve Simon

 

Microsoft Excel Pivot Tables

*Blog post
2004
Statistical computing
Someone at my church wanted some advice about exploring relationships in a survey that he had taken. He asked a bunch of demographic questions (age, sex, income, etc.) and…
Aug 5, 2004
Steve Simon

 

Searching for bimodality

*Blog post
2004
Statistical theory
One of the people I work with is always looking for hidden subgroups in his data. For him, this is a starting point for exploring for genetic variations.
Aug 4, 2004
Steve Simon

 

So you want to volunteer for a research study?

*Blog post
2004
Exclusions in research
Here’s a draft of a speech that I am planning to give on August 5, 2004 for the Bluejacket Toastmasters humorous speech competition.
Aug 4, 2004
Steve Simon

 

Secondary Uses of Data

*Blog post
2004
Privacy in research
Mark Barnes gave a seminar on August 2, 2004 on Secondary Uses of Biologic Materials and Medical Data by Researchers and Commercial Research Sponsors. Here are my notes…
Aug 2, 2004
Steve Simon

 

Breaking the blind

*Blog post
2004
Blinding in research
Someone asked an interesting question on the IRBForum today. Under what circumstances should the blinding for a trial be broken when an unexpected Serious Adverse Event…
Jul 29, 2004
Steve Simon

 

Statalist

*Blog post
2004
Statistical computing
I recently upgraded to version 8 of Stata, which is a nice program for advanced statistical analyses. During the registration of the software, the program asked me if I…
Jul 29, 2004
Steve Simon

 

Evaluating the AUC for an ROC curve

*Blog post
2004
Diagnostic testing
Someone asked me where I got the following guidance for Area Under the Curve (AUC) for a Receiver Operating Characteristic (ROC) curve.
Jul 27, 2004
Steve Simon

 

Confidence intervals for proportions

*Blog post
2004
Confidence intervals
One of the fellows at the hospital asked me about confidence intervals for proportions. I wrote a couple of simple spreadsheets to do these calculations
Jul 27, 2004
Steve Simon

 

Random identification numbers

*Blog post
2004
Randomization
Someone asked me today for a set of random numbers. The purpose was to create an ID code that could be used to track back to the original records to resolve any…
Jul 26, 2004
Steve Simon

 

Sample size calculations in studies with a baseline

*Blog post
2004
Sample size justification
Many research studies evaluate all patients at baseline and then randomly assign the patients to groups, conduct the interventions, and then re-evaluate them at the end of…
Jul 23, 2004
Steve Simon

 

Is there a mechanism?

*Blog post
2004
Corroborating evidence
“Extraordinary claims require extraordinary proof.” This is the mantra of skeptical thinkers and it provides useful for evaluating claims that fall outside the mainstream of…
Jul 23, 2004
Steve Simon

 

Retrospective chart reviews and IRB approval

*Blog post
2004
Privacy in research
Someone stopped by today with a question about getting IRB approval for a retrospective chart review. They were interested in examining the efficacy of a certain drug that…
Jul 21, 2004
Steve Simon

 

Conflict of interest

*Blog post
2004
Conflict of interest
Does having a commercial interest in the results of a drug trial cause a problem for the people running the trial? If it does, then much of the research that we rely on…
Jul 20, 2004
Steve Simon

 

Aliasing patterns

*Blog post
2004
Statistical computing
When you draw lines and curves on a computer screen, most of them end up with a subtle staircase pattern because you are using discrete pixels to represent a smooth line or…
Jul 19, 2004
Steve Simon

 

Bluejacket Toastmasters Speech

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jul 15, 2004
Steve Simon

 

Bluejacket Toastmasters speech

*Blog post
2004
Presenting research
This is the text of a talk I gave to Bluejacket Toastmasters on July 15, 2004.
Jul 15, 2004
Steve Simon

 

Adaptive randomization

*Blog post
2004
Equipoise in research
Randomization
Someone on the IRBForum posed a theoretical question. Is running a three arm study troublesome from an ethical viewpoint because the probability that any subject in the…
Jul 15, 2004
Steve Simon

 

Randomization test

*Blog post
2004
Unusual data
I received some data from a project where the outcome measure was the degree of improvement after a treatment, with values of -1 (slight decline), 0 (no change), 1 (slight…
Jul 14, 2004
Steve Simon

 

Provisional means algorithm

*Blog post
2004
Statistical computing
One of the new fellows asked me about a data summary for two groups of patients. The ages were quite different, the mean age was 4.6 years in the exposure group and 8.5…
Jul 9, 2004
Steve Simon

 

Testing for side effects

*Blog post
2004
Being updated
(To be added)
Jul 8, 2004
Steve Simon

 

Testing for side effects

*Blog post
2004
Being updated
(To be added)
Jul 8, 2004
Steve Simon

 

Planning a qualitative research study

*Blog post
2004
Qualitative research
Someone asked me for some specific advice on how to design a qualitative study. I love qualitative research. I think people should be using this mode of research more often.…
Jul 6, 2004
Steve Simon

 

Sample size for a diagnostic test

*Blog post
2004
Sample size justification
Someone asked me how to determine the sample size for a study involving a diagnostic test. It seems like a tricky thing, because most studies of diagnostic tests don’t have…
Jul 5, 2004
Steve Simon

 

Early stopping in an animal study

*Blog post
2004
Early stopping
Rmarkdown code
I was helping someone with power calculations for an animal experiment. There were several ways to estimate power and they all seemed to point to the use of either 8 animals…
Jul 1, 2004
Steve Simon

 

Lost page

*Blog post
2004
Being updated
Earlier versions are here and here.
Jul 1, 2004
Steve Simon

 

Small relative risk

*Blog post
2004
Corroborating evidence
Someone asked me about small relative risk. It was only 1.12, but because of the large sample size, it was still statistically significant. This person wanted to discount…
Jun 30, 2004
Steve Simon

 

Nonlinear Least Squares in S-plus and R

*Blog post
2004
Nonlinear regression
I’ve worked on a brief explanation of how to fit an S-shaped curve using SPSS and someone wanted to know how to do this in R.
Jun 28, 2004
Steve Simon

 

Excluding placebo responders

*Blog post
2004
Exclusions in research
Placebos in research
I’ve always been fascinated by the placebo effect and the ethical issues associated with use of placebos in research.
Jun 25, 2004
Steve Simon

 

Publication bias

*Blog post
2004
Publication bias
Eliot Spitzer, New York’s state attorney general has filed a lawsuit against GlaxoSmithKline for concealing negative trials about an antidepressant that the company…
Jun 25, 2004
Steve Simon

 

Pap smears for women without a cervix

*Blog post
2004
Diagnostic testing
In the most recent issue of JAMA is an article by Sirovich and Welch, Cervical Cancer Screening Among Women Without a Cervix [Abstract] that estimates almost 10 million…
Jun 24, 2004
Steve Simon

 

Lost page

*Blog post
1999
Being updated
You can find an earlier version of this page on my website.
Jun 24, 2004
Steve Simon

 

The impact of XML on Statistics

*Blog post
2004
Statistical computing
XML (eXtensible Markup Language) is standard for sorting information that has the flexibility needed to handle complex data. It is similar to HTML (HyperText Markup…
Jun 23, 2004
Steve Simon

 

Missing values

*Blog post
2004
Statistical theory
Someone here at the hospital asked me how to do a reliability analysis on a 20 item measure where a large number of participants left a single item blank. There are several…
Jun 22, 2004
Steve Simon

 

McNemar’s Test

*Blog post
2004
Unusual data
I received an email asking how to test two correlated proportions to see if one proportion is significantly larger than another. This is a classic application of McNemar’s…
Jun 17, 2004
Steve Simon

 

Data Mining with Clementine

*Blog post
2004
Data mining
Statistical computing
I attended an SPSS web seminar about their Clementine program, which performs data mining. The talk was oriented to business applications, but still had some interesting…
Jun 15, 2004
Steve Simon

 

Evidence-based Complementary and Alternative Medicine

*Blog post
2004
Teaching resources
There’s a new journal out with free full text on the web. It is Evidence-based Complementary and Alternative Medicine and is published by Oxford Journals online. I find that…
Jun 15, 2004
Steve Simon

 

Statistical consulting

*Blog post
2004
Teaching resources
Most training programs in Statistics do a good job in emphasizing the various tools that you will need, but it is much harder to teach the nonstatistical aspects of…
Jun 14, 2004
Steve Simon

 

Categorical variables in a logistic regression model

*Blog post
2004
Logistic regression
On April 8, I had written a brief description of interactions in a logistic regression model. This was a supplement to a discussion of the concepts behind the logistic…
Jun 1, 2004
Steve Simon

 

Monte Carlo methods

*Blog post
2004
Statistical computing
I got a question from someone in my office who is taking a class on research methods. She asked me to define the term “Monte Carlo” that her teacher had used without much of…
May 31, 2004
Steve Simon

 

Health effects of smoking

*Blog post
2004
Corroborating evidence
A recent Surgeon’s General report on smoking adds new cause-and-effect links between smoking and several diseases including cataracts, pneumonia, acute myeloid leukemia…
May 31, 2004
Steve Simon

 

What is information theory

*Blog post
1999
Being updated
Information theory
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 26, 2004
Steve Simon

 

Analyzing percentage data

*Blog post
2004
Unusual data
I received one of those difficult to answer questions: how do I analyze my data when the outcome variable is a percentage. That depends a lot on the context of the problem.
May 24, 2004
Steve Simon

 

Sample size calculation example

*Blog post
2004
Sample size justification
I received a question in Hong Kong about how to double check a power calculation in a paper by Tugwell et al in the 1995 NEJM.
May 20, 2004
Steve Simon

 

Goodness of fit test

*Blog post
2004
Measuring agreement
The chi-square test appears in a lot of different places. Some recent data on Astrology, published in the May newsletter of the Skeptic Society, offers an interesting…
May 18, 2004
Steve Simon

 

Correlations with categorical variables

*Blog post
2004
Descriptive statistics
I got another question, this one from Brooklyn, New York. It’s a commonly asked question, so I should write something about this. The question is whether you can get a…
May 13, 2004
Steve Simon

 

Sample size for a survival data model

*Blog post
2004
Sample size justification
I got an email from Japan recently with an interesting question. By the way, one of the fun things about my web pages is that I get emails from all over the world. I can…
May 13, 2004
Steve Simon

 

Advanced SPSS methods

*Blog post
2004
SPSS software
SPSS had a nice web seminar on their Regression and Advanced Statistics modules. Here are some notes that I took while sitting in.
May 12, 2004
Steve Simon

 

Information Theory Models

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 11, 2004
Steve Simon

 

Information Theory Examples

*Blog post
2004
Being updated
The formula for uncertainty (sometimes referred to as entropy) is
May 11, 2004
Steve Simon

 

Notes from JSM 2004

*Blog post
2004
Being updated
This page is crrently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 11, 2004
Steve Simon

 

Response to Olshansky and Dossey

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
May 11, 2004
Steve Simon

 

Information Theory

*Blog post
2004
Being updated
Information theory
The formula for uncertainty (sometimes referred to as entropy) is
May 10, 2004
Steve Simon

 

Acuity microarray analysis software.

*Blog post
2004
Data mining
Statistical computing
I got a request to evaluate some software by Axon Instruments for the analysis of microarray data. The software, Acuity version 3.1, costs $4,000 per person and has to…
May 6, 2004
Steve Simon

 

Overlooking one’s own flaws

*Blog post
2004
Critical appraisal
Can we ever be truly objective about ourselves? Maybe not. A recent article in Scientific American by Michael Shermer, The Enchanted Glass, talks about the tendency to see…
May 3, 2004
Steve Simon

 

Degrees of freedom, Part 2

*Blog post
2004
Statistical theory
I received an email inquiry about degrees of freedom. I explain the concept briefly, but this person wanted a more detailed answer to the question, why do we use n-1 in the…
Apr 15, 2004
Steve Simon

 

The Wikipedia

*Blog post
2004
Teaching resources
Part of my job on these web pages is to find good resources beyond what I can write about Statistics. I’m finding more and more that there are wonderful references in a web…
Apr 15, 2004
Steve Simon

 

Focus groups and qualitative research

*Blog post
2004
Qualitative research
A student is giving a talk on focus groups and asked me a few questions about my attitude towards them. I think focus groups are great. They give you a richer picture of the…
Apr 13, 2004
Steve Simon

 

Clinically trivial effects

*Blog post
2004
Clinical importance
I don’t like to cite articles in the New York Times, because they are free on the web only for a couple of weeks. But an article by Denise Grady, Nominal Benefits Seen in…
Apr 12, 2004
Steve Simon

 

One-tailed p-values

*Blog post
2004
Hypothesis testing
Someone asked me how to compute one-sided p-values in SPSS. The output from SPSS always uses two-sided p-values. This was worth an explanation, so I added a new question to…
Apr 12, 2004
Steve Simon

 

One tailed p-values

*Blog post
2004
Pvalues
Dear Professor Mean, SPSS produces two-tailed p-values, but I want a one-tailed p-value. How do I get this?
Apr 12, 2004
Steve Simon

 

A serious problem of publication bias

*Blog post
2004
Publication bias
I was browsing a paper by Leonard Leibovici [Medline] about alternative medicine when a comment by Andrew Vickers in the eletters section caught my eye. He noted the serious…
Apr 9, 2004
Steve Simon

 

Interactions in logistic regression

*Blog post
2004
Logistic regression
Someone asked me how to compute interactions in binary logistic regression. You need to be careful, since interactions are tricky to interpret. I need to update my pages to…
Apr 8, 2004
Steve Simon

 

Temporality of Causes

*Blog post
2004
Corroborating evidence
One of the nine criteria that Sir Austin Bradford Hill offers to establish a cause and effect relationship is temporality. In order for A to cause B, A must precede B in…
Apr 7, 2004
Steve Simon

 

Constraints on Randomization

*Blog post
2004
Randomization
I received an inquiry from our Institutional Review Board about a study they were doing a continuing review for. This was a non-randomized comparison of two surgical…
Mar 23, 2004
Steve Simon

 

Evidence-based lessons learned from Cardiology

*Blog post
2004
Teaching resources
There was a nice series of articles in the journal Circulation that appeared in 2002 with free full text online. These articles offer specific lessons about evidence-based…
Mar 18, 2004
Steve Simon

 

Steps in a typical microarray analysis

*Blog post
1999
Being updated
Data mining
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 17, 2004
Steve Simon

 

EM Algorithm

*Blog post
2004
Statistical computing
I received an email question about the EM Algorithm. This is a computational approach that works well for missing data problems and data models with latent (unobserved)…
Mar 15, 2004
Steve Simon

 

Steps for establishing a quality control program

*Blog post
2004
Quality control
So you’ve decided to implement a quality control program in your laboratory. What will it take to make that program successful? There are three steps, and you must follow…
Mar 12, 2004
Steve Simon

 

Steps for establishing a quality control program

*Blog post
1999
Being updated
Quality control
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Mar 12, 2004
Steve Simon

 

Central Limit Theorem

*Blog post
2004
Modeling issues
Dear Professor Mean, How does the central limit theorem affect the statistical tests that I might use for my data?
Mar 9, 2004
Steve Simon

 

Quality control in the laboratory

*Blog post
2004
Quality control
I’ll be giving a talk at the American Society for Andrology in April about the use of quality control for sperm morphology assessments. I’ll put some of my notes up on the…
Mar 9, 2004
Steve Simon

 

Parametric versus nonparametric tests

*Blog post
2004
Unusual data
One of the biggest areas of disagreement among statisticians is when to use parametric or non-parametric statistics. I got an inquiry about this today, and quite honestly, I…
Mar 9, 2004
Steve Simon

 

Conflict of Interest

*Blog post
2004
Conflict of interest
The New York Review of Books has a extensive review written by Richard Horton of the book Science in the Private Interest: Has the Lure of Profits Corrupted Biomedical…
Feb 25, 2004
Steve Simon

 

Evidence Based Medicine and Ethics

*Blog post
2004
Teaching Resources
The Journal of Medical Ethics has a series of articles about ethics and evidence based medicine. These are pre-prints of articles under review and you can prepare a response…
Feb 20, 2004
Steve Simon

 

Number needed to harm examples

*Blog post
2004
Measuring benefit and risk
I was trying to track down a reference on the NNH (number needed to harm) for antibiotic use, but noticed instead the large number of good examples of NNH calculations in…
Feb 18, 2004
Steve Simon

 

S-shaped curves

*Blog post
2004
Nonlinear regression
Competitive binding experiments will often need a nonlinear regression model. This model has to level off at both extremes to represent almost no binding at one end and…
Feb 12, 2004
Steve Simon

 

Enumerative and Analytic Studies

*Blog post
2004
Descriptive statistics
Research design
I received a question today via email about what statistics you can use when your sample equals the entire population. This issue also comes up when people ask about the use…
Feb 5, 2004
Steve Simon

 

Educational Resources

*Blog post
2004
Teaching resources
Someone posed a question on the IRB Discussion forum wondering if there was a source of free materials “that we can email or distribute as hardcopy to our study coordinators…
Feb 3, 2004
Steve Simon

 

Brief Biography

*Blog post
2004
Professional details
Steve Simon earned a Ph.D. in Statistics from the University of Iowa in 1982. He currently works as a research biostatistician at Childrens Mercy Hospitals and Clinics in…
Jan 14, 2004
Steve Simon

 

Steps in establishing validity/reliability

*Blog post
1999
Being updated
Measuring agreement
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 13, 2004
Steve Simon

 

Craniosacral therapy

*Blog post
2004
Being updated
(To be added)
Jan 1, 2004
Steve Simon

 

In vitro fertilization prayer study

*Blog post
2004
Being updated
(To be added)
Jan 1, 2004
Steve Simon

 

What’s a good value for Cronbach’s Alpha?

*Blog post
2004
Being updated
(To be added)
Jan 1, 2004
Steve Simon

 

Deaf chairs, lost cake recipes, and a letter from Maria.

*Blog post
2004
Being updated
(To be added)
Jan 1, 2004
Steve Simon

 

I hate PowerPoint

*Blog post
2004
Being updated
(To be added)
Jan 1, 2004
Steve Simon

 

Weblog entries from the 2004 JSM

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2004
Steve Simon

 

In vitro fertilization prayer study

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2004
Steve Simon

 

My efforts to kill PowerPoint

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2004
Steve Simon

 

Recent updates

*Blog post
2004
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2004
Steve Simon

 

Steps in a typical equivalence data analysis

*Blog post
2003
Hypothesis testing
Incomplete page
There are three approaches that are used to demonstrate equivalence, each with its advantages and disadvantages.
Nov 27, 2003
Steve Simon

 

Accuracy of computations

*Blog post
2003
Statistical computing
I’ve heard a lot about accuracy problems with Microsoft Excel, but I’d like to see an example where this really is a problem.
Nov 26, 2003
Steve Simon

 

Data is/are

*Blog post
2003
Broken link
Writing research papers
Should I write “data is” or “data are”?*
Nov 26, 2003
Steve Simon

 

A simple model of nonlinear growth

*Blog post
2003
Nonlinear regression
Part of the challenge in nonlinear regression is to choose the correct form of the nonlinear relationship. Part of this is intuition, part of this is understanding some…
Oct 1, 2003
Steve Simon

 

Steps in a typical data mining model

*Blog post
2003
Broken link
Data mining
Incomplete page
I’m not an expert on data mining, but I wanted to outline some of the basic issues associated with data mining problems. This material is based largely on notes that I took…
Sep 22, 2003
Steve Simon

 

An introduction to diagnostic testing

*Blog post
2003
Being updated
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 8, 2003
Steve Simon

 

SPSS syntax for Poisson Regression, Marta Garcia-Granero, PhD

*Blog post
2003
Poisson regression
Obsolete page
Note: you can now run Poisson regression directly from the SPSS menus, so this syntax is no longer needed. I am keeping it here because I am an electronic packrat.
Jul 29, 2003
Steve Simon

 

Mean or median?

*Blog post
2003
Descriptive statistics
I am writing a report on turnover. I want to summarize the number of weeks it takes to fill a vacancy. Should I use a mean or a median?
Jul 28, 2003
Steve Simon

 

What does “overfitting” mean?

*Blog post
2003
Modeling issues
I am conducting binary logistic regression analyses with a sample size of 80 of which 20 have the outcome of interest (e.g. are “very successful” versus somewhat/not very…
Jul 24, 2003
Steve Simon

 

Steps in a typical ANOVA model

*Blog post
2003
Analysis of variance
I wanted to compare two groups in my research, those who completed every test battery, and those who completed only some of them. I ran ANOVAs on age, iq, adhd score, and so…
Jun 20, 2003
Steve Simon

 

Pitch the pie! Ban the bar!

*Blog post
2003
Descriptive statistics
Graphical display
This is an outline of a speech that I gave to Bluejacket Toastmasters on June 5, 2003.
Jun 5, 2003
Steve Simon

 

Skewed data

*Blog post
2003
Descriptive statistics
Please explain how the standard deviation can be greater than the mean. I think it is because of skewed data.*
Jun 5, 2003
Steve Simon

 

Cluster randomization

*Blog post
2003
Sample size justification
One of my favorite people to work with, Vidya Sharma, was asking me how to compute the sample size in a cluster randomized trial. I had started to write a web page about…
May 9, 2003
Steve Simon

 

Cluster randomization

*Blog post
2003
Sample size justification
One of my favorite people to work with, Vidya Sharma, was asking me how to compute the sample size in a cluster randomized trial. I had started to write a web page about…
May 9, 2003
Steve Simon

 

Maximum likelihood estimation

*Blog post
2003
Statistical theory
What is maximum likelihood estimation and how does it work?*
May 6, 2003
Steve Simon

Maximum likelihood estimation

*Blog post
2003
Statistical theory
Dear Professor Mean, What is maximum likelihood estimation and how does it work?
May 6, 2003
Steve Simon

 

Obsolete! CMH Consulting Services

*Blog post
Obsolete page
2003
Professional details
This page is obsolete, but I am keeping it around because I am an electronic pack rate.
Apr 30, 2003
Steve Simon

 

Why informed consent is important

*Blog post
2003
Ethics in research
To understand why researchers today must obtain informed consent from their patients before they subject them to experiments, you need to understand some of the previous…
Apr 30, 2003
Steve Simon

 

Building a complex model

*Blog post
2003
Linear regression
When you have a lot of variables that might possibly influence your outcome, your desire is to find some automated procedure that will select your model for you. Using an…
Apr 23, 2003
Steve Simon

 

Coding race/ethnicity

*Blog post
2003
Broken link
Data management
If you have to collect data on the race and/or ethnicity of your research subjects, you should be aware of the official U.S. government definitions that all federal agencies…
Feb 3, 2003
Steve Simon

 

Diagnostic

*Blog post
2003
Website details
This page provides resources for a small booklet I have developed, “An introduction to diagnostic testing.” I have printed a few of these booklets and attached a fully…
Jan 1, 2003
Steve Simon

 

Displaying tables of percentages

*Blog post
2002
Ask Professor Mean
Descriptive statistics
Writing research papers
Dear Professor Mean, My colleagues and I argue over the most appropriate way for displaying tables of percentages. Must the row or column always add to 100%? Also in cases…
Nov 6, 2002
Steve Simon

 

Post hoc power

*Blog post
2002
Post hoc power
Dear Professor Mean, The results of my study were negative, and the journal reviewer insists that I perform a post hoc power calculation. How do I do this? -Jittery Jerry
Nov 1, 2002
Steve Simon

 

Likelihood ratio slide rule

*Blog post
2008
Being updated
Likelihood ratio slide rule
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 24, 2002
Steve Simon

 

Log transformation

*Blog post
2002
Ask Professor Mean
Modeling issues
Dear Professor Mean, I have some data that I need help with analysis. One suggestion is that I use a log transformation. Why would I want to do this?
Oct 11, 2002
Steve Simon

 

Steps in a typical survival data analysis

*Blog post
2002
Survival analysis
There are three steps in a typical survival analysis.
Oct 11, 2002
Steve Simon

 

Checking the assumption of normality

*Blog post
2002
Ask Professor Mean
Modeling issues
Dear Professor Mean, I have some data that don’t seem to meet the assumption of normality. What should I do?
Sep 11, 2002
Steve Simon

 

Data management for survival data

*Blog post
2002
Being updated
Survival analysis
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 27, 2002
Steve Simon

 

Exploring interactions in a linear regression model

*Blog post
2002
Ask Professor Mean
Linear regression
Dear Professor Mean, I have a model with two factors. When I ran the model, it showed a significant interaction between the two factors. What do I do now?
Aug 1, 2002
Steve Simon

 

Longitudinal data

*Blog post
2002
SPSS software
Dear Professor Mean, I have longitudinal data on the growth pattern of patients given growth hormone. How should I store the data? –Jittery Jerry
Jul 26, 2002
Steve Simon

 

The concepts behind the logistic regression model

*Blog post
2002
Incomplete pages
Logistic regression
The logistic regression model is a model that uses a binary (two possible values) outcome variable. Examples of a binary variable are mortality (live/dead), and morbidity…
Jul 23, 2002
Steve Simon

 

SPSS dialog boxes for logistic regression

*Blog post
2002
Logistic regression
This handout shows some of the dialog boxes that you are likely to encounter if you use logistic regression models in SPSS.
Jul 22, 2002
Steve Simon

 

Privacy concerns in research

*Blog post
2002
Ask Professor Mean
Privacy in research
Dear Professor Mean, I want to do some research using tissue samples, but the Institutional Review Board has said that I have to get consent first, because the data are not…
Jul 12, 2002
Steve Simon

 

So you want to write a questionnaire

*Blog post
2002
Survey design
Dear Professor Mean, I need to write a questionnaire for a research study I am conducting. Can you help me write it? – Cautious Carmen
Jul 12, 2002
Steve Simon

 

Interpreting coefficients in a linear regression model

*Blog post
2002
Linear regression
When I ask most people to remember their high school algebra class, I get a mixture of reactions. Most recoil in horror. About one in every four people say they liked that…
Jun 24, 2002
Steve Simon

 

Interpreting coefficients in a linear regression model

*Blog post
1999
Being updated
Earlier versions are here and here.
Jun 24, 2002
Steve Simon

 

SPSS dialog boxes for a descriptive analysis

*Blog post
2002
Descriptive Statistics
This handout will show the SPSS dialog boxes that I used to create the examples in the descriptive data analysis handout. I will capitalize variable names, field names and…
Jun 21, 2002
Steve Simon

 

SPSS dialog boxes for linear regression models

*Blog post
2002
Linear regression
This handout will show the SPSS dialog boxes that I used to create linar regression examples. I will capitalize variable names, field names and menu picks for clarity.
Jun 21, 2002
Steve Simon

 

Why 95% confidence limits?

*Blog post
2002
Ask Professor Mean
Confidence intervals
Dear Professor Mean, I’ve been working with small data sets for some neuroimaging research that have 5 treatment and 5 control participants. It is not unusual to have such…
May 6, 2002
Steve Simon

 

SPSS citation

*Blog post
2002
Ask Professor Mean
SPSS software
Dear Professor Mean, I’m writing a research paper. When I talk about the statistical methods, how do I properly cite the use of SPSS software? And just what does SPSS stand…
Mar 6, 2002
Steve Simon

 

Biography

*Blog post
2002
Professional details
Steve Simon earned a PhD in Statistics from the University of Iowa in 1982. His training emphasized applied statistics and he served for two years as the student head of the…
Jan 16, 2002
Steve Simon

 

Stopping a study early

*Blog post
2002
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2002
Steve Simon

 

Getting IRB approval for your research

*Blog post
2002
Incomplete pages
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2002
Steve Simon

 

Establishing validity and reliability

*Blog post
2002
Ask Professor Mean
Incomplete page
Measuring agreement
Dear Professor Mean, I need to establish validity and reliability of a new measurement. How do I do this?
Jan 1, 2002
Steve Simon

 

Statistical Training Opportunities At Children’s Mercy Hospital

*Blog post
2008
Obsolete page
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Nov 5, 2001
Steve Simon

 

Unequal group sizes

*Blog post
2001
Being updated
Analysis of variance
Dear Professor Mean, I am comparing several groups of subjects, but the number of subjects in each group differ quite a bit. How does this affect the assumptions in analysis…
Nov 2, 2001
Steve Simon

 

BMJ letter

*Blog post
2001
Being updated
Randomization in research
Here’s a letter I submitted to the web letters to the editor for the British Medical Journal in response to an article about randomisation (BMJ 1999 Sep 11;319(7211):703-704).
Oct 11, 2001
Steve Simon

 

Problems with a very small sample

*Blog post
2001
Being updated
Small sample size issues
Dear Professor Mean, Are there problems with a very small sample? Can the t-test be used with a sample of just three subjects? – Anxious Abdelwahab
Oct 11, 2001
Steve Simon

 

Steps in a descriptive model

*Blog post
2001
Being updated
Descriptive statistics
Every data analysis should start with a descriptive or exploratory analysis. If you have no research hypotheses, then you can stop with this. If you do have research…
Oct 11, 2001
Steve Simon

 

Parametric versus nonparametric tests

*Blog post
2001
Being updated
Unusual data
Dear Professor Mean, When should I use a parametric test versus a non-parametric test?
Jul 30, 2001
Steve Simon

 

Web polls

*Blog post
2001
Being updated
Research design
Dear Professor Mean, I’m conducting a number of web-based polls and would like to include a margin of error in my results. How do I do this?
Jul 30, 2001
Steve Simon

 

Loading ODBC drivers from the Microsoft Data Access Pack

*Blog post
2001
Being updated
Data management
SPSS software
This page is obsolete, but I am keeping it here for sentimental reasons.
Jan 24, 2001
Steve Simon

 

The minimal impact of population size on power and precision

*Blog post
2001
Confidence intervals
Rmarkdown code
Sample size justification
Can you explain why it is okay to have similar sample sizes for populations of very different sizes. For example, why is it that a sample size for a population of 10 million…
Jan 19, 2001
Steve Simon

 

Confidence interval with zero events

*Blog post
2005
Confidence intervals
Dear Professor Mean, I was working with a colleague on some confidence intervals for the probability of an adverse event during several different types of operations. One of…
Jan 19, 2001
Steve Simon

 

Writing the methods section of your grant

*Blog post
2001
Being updated
Incomplete page
Writing research grants
Dear Professor Mean, I’m starting to write the methods section for a research grant, but I have no idea where to start. – Dazed Dana
Jan 15, 2001
Steve Simon

 

Odds ratio versus relative risk

*Blog post
2001
Being updated
Measuring benefit and risk
Dear Professor Mean: There is some confusion about the use of the odds ratio versus the relative risk. Can you explain the difference between these two numbers?
Jan 9, 2001
Steve Simon

 

Documenting negative results in a research paper

*Blog post
2001
Being updated
Website details
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 1, 2001
Steve Simon

 

Ethics of a placebo group

*Blog post
2001
Being updated
Website details
Dear Professor Mean, Some of my colleagues want to use placebos in their research, but I have warned them about the ethical issues surrounding the use of a placebo group.…
Jan 1, 2001
Steve Simon

 

Quick sample size calculations

*Blog post
2001
Being updated
Website details
Dear Professor Mean, I’m reading a research paper. I suspect that the sample size is way too small. I don’t like the findings of the study anyway, so I’m hoping that you…
Jan 1, 2001
Steve Simon

 

Three things you need for a power calculation

*Blog post
2001
Being updated
Website details
Dear Professor Mean, I want to do research. Is forty subjects enough, or do I need more? Eager Edward
Jan 1, 2001
Steve Simon

 

*Blog post
2000
Incomplete page
Quality improvement
This page is being updated.
Dec 27, 2000
Steve Simon

 

*Blog post
2000
Quality improvement
This page is being updated.
Dec 27, 2000
Steve Simon

 

*Blog post
2000
Quality improvement
This page is being updated.
Dec 27, 2000
Steve Simon

 

*Blog post
2000
Quality improvement
This page is being updated.
Dec 27, 2000
Steve Simon

 

Protocol changes.

*Blog post
2000
Early stopping
Dear Professor Mean, After I collected my data, I noticed a problem that I had not anticipated. I want to make some protocol changes and analyze my data differently. Can I…
Dec 22, 2000
Steve Simon

 

Sample size for the Mann-Whitney U test

*Blog post
2000
Sample size justification
Dear Professor Mean, I need to calculate the sample size for the Mann-Whitney U test. How do I do this? – Bewildered Bob
Sep 28, 2000
Steve Simon

 

Software used to create these web pages.

*Blog post
2000
Obsolete page
Website details
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Aug 24, 2000
Steve Simon

 

Binary outcome sample size calculations

*Blog post
2000
Being updated
Sample size justification
*Dear Professor Mean, I have to calculate a sample size for a binary outcome variable. The research study is on breast feeding failures within 7 to 10 days of birth for…
Aug 23, 2000
Steve Simon

 

Stratified random sample.

*Blog post
2000
Ask Professor Mean
Research design
Dear Professor Mean, What is a stratified random sample and why would I want to use one?
Aug 23, 2000
Steve Simon

 

Fisher’s Exact Test

*Blog post
2000
Logistic regression
Dear Professor Mean, What is Fisher’s Exact Test and when should I use it?
Aug 23, 2000
Steve Simon

 

Alternating treatments

*Blog post
2000
Ask Professor Mean
Randomization
Dear Professor Mean, I’m running an experiment where I randomize by alternating between the treatment and the control. I was told this is not the proper way to do this. Why…
Aug 22, 2000
Steve Simon

 

What is the Kaplan Meier curve?

*Blog post
2000
Ask Professor Mean
Survival analysis
Dear Professor Mean, When I read my medical journals, I keep on coming across terms like Kaplan-Meier Product Limit estimate or Kaplan-Meier survival curve. What do these…
Jun 27, 2000
Steve Simon

 

Links from other sites

*Blog post
2000
Website details
Website details
It’s flattering when someone recommends my site, so I keep track of this here. I also want to keep tabs on these links so when I change a page name, I am sure that it…
Feb 2, 2000
Steve Simon

 

Acknowledgements

*Blog post
2000
Website details
These web pages have several Sherlock Holmes quotes. These quotes can be found in the marvelous book Statistically Speaking. A Dictionary of Quotations, by C.C. Gaither and…
Jan 28, 2000
Steve Simon

 

Copyright notice

*Blog post
2000
Website details
This page is obsolete and is being included only for historical purposes. The proper copyright notice is included in the footer for every page.
Jan 28, 2000
Steve Simon

 

Exporting SPSS graphs and tables.

*Blog post
2000
Data management
SPSS software
Dear Professor Mean, I need to export the output from SPSS and use some of it in my word processing file. What is the best way to do this? – Manic Marsha
Jan 28, 2000
Steve Simon

 

Important disclaimer.

*Blog post
2000
Website details
Although I work in a hospital, my profession is Statistics. I help the doctors and nurses here plan research studies and make sense of the numbers after the research is done. …
Jan 28, 2000
Steve Simon

 

Quota stratified random sampling.

*Blog post
2000
Ask Professor Mean
Research design
Dear Professor Mean, I’m doing my thesis right now and I have to use quota stratified random sampling. I do not know the exact meaning of this term.
Jan 28, 2000
Steve Simon

 

Outliers

*Blog post
2000
Ask Professor Mean
Unusual data
Dear Professor Mean, I have recently conducted a survey of attitudes toward research from a professional group. There are some outliers (+/- 3SD) that I would eliminate …
Jan 28, 2000
Steve Simon

 

Spreadsheet or Database?

*Blog post
2000
Ask Professor Mean
Data management
Dear Professor Mean, I am not sure whether I should use a database or a spreadsheet to enter my data?
Jan 28, 2000
Steve Simon

 

Association versus causation

*Blog post
2000
Ask Professor Mean
Corroborating evidence
Dear Professor Mean, Everyone says that smoking causes cancer, but we can’t really say that, can we? There is an association between smoking and cancer, but we know that…
Jan 27, 2000
Steve Simon

 

Composite scores

*Blog post
2000
Unusual data
I have developed a method to distinguish among several products that we need to buy so our company can make a good purchasing decision. I created a composite score which is…
Jan 27, 2000
Steve Simon

 

Sigma in the control chart.

*Blog post
2000
Ask Professor Mean
Control charts
Dear Professor Mean, I ran a control chart in SPSS for individual values, and the control limits don’t correspond with what I would expect from the descriptive procedure…
Jan 27, 2000
Steve Simon

 

Physician Performance Data

*Blog post
2000
Unusual data
Dear Professor Mean, Producing statistics of physician performance or group performance or whatever seems to be one of the great growth industries in medicine. Graphs of…
Jan 27, 2000
Steve Simon

 

Regression to the mean

*Blog post
2000
Ask Professor Mean
Linear regression
Dear Professor Mean, In a stat course I was introduced to the term “regression to the mean”. Today we administered a pretest to 4th graders. In Feb we will again test, with…
Jan 27, 2000
Steve Simon

 

Flaws in a research paper

*Blog post
2000
Critical appraisal
Dear Professor Mean, A small group I’ve been teaching has gotten extremely interested in how to decide when there are too many flaws in a paper which would completely…
Jan 27, 2000
Steve Simon

 

Jargon in Statistics

*Blog post
2000
Ask Professor Mean
Critical appraisal
Dear Professor Mean, I have to review a paper for journal club and I don’t understand all the obscure statistical jargon that the authors use.
Jan 27, 2000
Steve Simon

 

Bootstrap

*Blog post
Ask Professor Mean
2000
Unusual data
Dear Professor Mean, I’ve heard a lot about how the bootstrap is going to revolutionize Statistics.
Jan 27, 2000

 

What is collinearity?

*Blog post
2000
Ask Professor Mean
Modeling issues
Dear Professor Mean, Could you describe the term collinearity for me? I understand that it has to do with variables which are not totally independent, but that is all I know!
Jan 27, 2000
Steve Simon

 

Intention to treat

*Blog post
2000
Ask Professor Mean
Measuring benefit and risk
Dear Professor Mean, I’m confused by medical journal articles that talk about the use of “Intention to Treat” analysis. What does this term mean?
Jan 27, 2000
Steve Simon

 

Mixture models

*Blog post
2000
Ask Professor Mean
Unusual data
Dear Professor Mean, I have read a journal article where the authors used a mixture model . What is this?
Jan 27, 2000
Steve Simon

 

Number Needed to Treat

*Blog post
2000
Ask Professor Mean
Measuring benefit and risk
Dear Professor Mean, How are patients and their doctors supposed to decide whether a research finding has practical significance? Why don’t the medical journals make things…
Jan 27, 2000
Steve Simon

 

Splines

*Blog post
2000
Ask Professor Mean
Unusual data
Dear Professor Mean, Can you send me a basic definition of splines?
Jan 27, 2000
Steve Simon

 

Stein’s paradox

*Blog post
2000
Being updated
Statistical theory
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Jan 27, 2000
Steve Simon

 

Best fitting curve

*Blog post
2000
Ask Professor Mean
Modeling issues
Dear Professor Mean, I have a graph of the trend for the mean frequency of injuries among children from 1 to 11 years of age. The shape of the curve suggests a nonlinear…
Jan 26, 2000
Steve Simon

 

Sample size for a confidence interval

*Blog post
2000
Ask Professor Mean
Confidence intervals
Sample size justification
Dear Professor Mean, We have a large dataset with about 400 million records. We need to randomly select a subsample from it. However we need help in determining the sample…
Jan 26, 2000
Steve Simon

 

Copyright

*Blog post
2000
Obsolete pages
Website details
This page is obsolete. My pages on the current website are placed into the public domain. I am keeping this page around mostly for nostalgic reasons.
Jan 1, 2000
Steve Simon

 

Future work on this website

*Blog post
2000
Website details
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Jan 1, 2000
Steve Simon

 

Obsolete webpages

*Blog post
2000
Website details
This page is being phased out. Look for the obsolete page tag on my new website.
Jan 1, 2000
Steve Simon

 

Information about myself

*Blog post
2000
Professional details
This page is obsolete, but I am keeping it around mostly for nostalgic reasons.
Jan 1, 2000
Steve Simon

 

My resume

*Blog post
2000
Professional details
This page is obsolete. I am keeping it around mostly for nostalgic reasons.
Jan 1, 2000
Steve Simon

 

Circular data models

*Blog post
1999
Being updated
Circular data
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Dec 15, 1999
Steve Simon

Meta-analysis for a diagnostic

*Blog post
1999
Being updated
Diagnostic testing
There is no real consensus yet on how to best combine data from several studies of a diagnostic test. I will outline a few approaches that seem to make sense.
Nov 15, 1999
Steve Simon

Meta-analysis for a diagnostic

*Blog post
1999
Being updated
Diagnostic testing
There is no real consensus yet on how to best combine data from several studies of a diagnostic test. I will outline a few approaches that seem to make sense. In addition to…
Nov 15, 1999
Steve Simon

 

Longitudinal data analysis

*Blog post
1999
Being updated
Multilevel models
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Oct 15, 1999
Steve Simon

Guidelines for logistic regression models

*Blog post
1999
Being updated
Logistic regression
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 27, 1999
Steve Simon

 

Injury index creation

*Blog post
1999
Unusual data
Dear Professor Mean, I want to create an injury index that describes the severity of an injury to a child. This would include information about the type of injury, the…
Sep 23, 1999
Steve Simon

Steps in a typical linear regression analysis

*Blog post
1999
Being updated
Linear regression
Let no man ignorant of geometry enter - Sign over Plato’s Academy in Athens
Sep 21, 1999
Steve Simon

Poisson regression model

*Blog post
1999
Being updated
Poisson regression
Dear Professor Mean, I have just received feedback on a manuscript under review in which one reviewer recommended use of Poisson regression. I am not familiar with this…
Sep 21, 1999
Steve Simon

Importing spreadsheet data into SPSS

*Blog post
1999
Being updated
Data management
SPSS software
Dear Professor Mean, I need to import data in an Excel spreadsheet, but I can’t get SPSS to read this data properly. Can you help? – Stumped Stan
Sep 20, 1999
Steve Simon

 

Where do research ideas come from? by Ronan Conroy

*Blog post
1999
Being updated
Grant writing
This is an HTML format version of an email by Ronan Conroy on April 9, 1999 to edstat-l, an Internet list and to sci.stat.edu, a USENET group. This email summarized a…
Sep 20, 1999
Steve Simon

Documenting your SPSS data sets

*Blog post
1999
Being updated
Data management
SPSS software
Dear Professor Mean, I need to add some documentation for SPSS data sets that I am creating. I know you covered this in your “Gentle Introduction to SPSS” class, but I’ve…
Sep 18, 1999
Steve Simon

Modifying SPSS data

*Blog post
1999
Being updated
Data management
SPSS software
Dear Professor Mean, Before I start my data analysis, I need to modify some of the data in my SPSS data set. I don’t want to re-type every number by hand. Is there a faster…
Sep 18, 1999
Steve Simon

Inputting a two-by-two table into SPSS

*Blog post
1999
Being updated
Data management
SPSS software
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 18, 1999
Steve Simon

 

Writing a research grant

*Blog post
1999
Being updated
Grant writing
Dear Professor Mean, I’m writing a research grant to look at the impact of managed care on the care of children with chronic epilepsy. How do I structure the grant so I’m…
Sep 13, 1999
Steve Simon

 

Interim analysis

*Blog post
1999
Being updated
Early stopping
Dear Professor Mean, I’m going on a job interview and I know one of the questions they will ask me is about interim analysis. What should I tell them? -- Harried Howard
Sep 13, 1999
Steve Simon

 

Type II error

*Blog post
1999
Being updated
Hypothesis testing
Dear Professor Mean, A journal reviewer criticized the small sample size in my research study and suggested that I mention a Type II error as a possible explanation for my…
Sep 13, 1999
Steve Simon

 

Asymmetric confidence intervals

*Blog post
1999
Being updated
Confidence intervals
Dear Professor Mean, I found a journal article with a confidence interval that was asymmetric. For example, the authors reported a mortality difference of 5% and a 95%…
Sep 3, 1999
Steve Simon

Sample size for a diagnostic study

*Blog post
1999
Being updated
Confidence intervals
Diagnostic testing
Sample size justification
Dear Professor Mean, How big should a study of a diagnostic test be? I want to estimate a sample size for the sensitivity and specifity of a test. I guess confidence…
Sep 3, 1999
Steve Simon

 

General guide to data entry

*Blog post
1999
Being updated
Data management
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 3, 1999
Steve Simon

 

Pilot study

*Blog post
1999
Being updated
Ask Professor Mean
Pilot studies
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Sep 3, 1999
Steve Simon

 

Bonferroni correction

*Blog post
1999
Being updated
Multiple comparisons
Dear Professor Mean, I keep reading about something called a Bonferroni correction. Somehow this method keeps researchers from going on a fishing expedition. Could you…
Sep 3, 1999
Steve Simon

 

Chi-squared test

*Blog post
1999
Being updated
Unusual data
Dear Professor Mean, Can the Chi-square test be used for anything besides categorical data?
Sep 3, 1999
Steve Simon

 

Degrees of Freedom

*Blog post
1999
Being updated
Statistical theory
Dear Professor Mean, In your Simple Descriptive Statistics class, you described the standard deviation as the square root of the average squared deviation. If it is an…
Sep 3, 1999
Steve Simon

 

E notation

*Blog post
1999
Being updated
Writing research papers
Dear Professor Mean, In my regression output, I saw that following value: -2.384E-03. What does this E notation mean?
Sep 3, 1999
Steve Simon

 

Page’s test

*Blog post
1999
Being updated
Unusual data
Dear Professor Mean, I have recently come across a statistical test (Page’s L test),with which I am unfamiliar. Does anyone either have information about this test or know…
Sep 3, 1999
Steve Simon

ROC curve

*Blog post
1999
Being updated
Diagnostic testing
Dear Professor Mean, I was at a meeting in Belgium and the buzz statistic was ROC Analysis. I think it stands for Receiver Operating Characteristic curve. It seems to be…
Aug 19, 1999
Steve Simon

 

All or nothing

*Blog post
1999
Being updated
Small sample size issues
This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.
Aug 18, 1999
Steve Simon

 

Date calculations in SPSS

*Blog post
1999
Being updated
Data management
SPSS software
Dear Professor Mean, I am trying to use dates in SPSS for certain calculations. For example, I want to use a compute statement in SPSS to create a new variable called…
Aug 18, 1999
Steve Simon

 

Importing database files into SPSS

*Blog post
1999
Being updated
Data management
SPSS software
Note: many of the details described here, may have changed. Every new version of SPSS and of Microsoft Windows makes small and sometimes large changes to the approach…
Aug 18, 1999
Steve Simon

 

Developing a research hypothesis

*Blog post
1999
Being updated
Grant writing
Dear Professor Mean, I want to do some research, but before the hospital won’t approve anything until I have a protocol with a research hypothesis. I’m not sure why a…
Aug 18, 1999
Steve Simon

How to randomize

*Blog post
1999
Being updated
Randomization
Dear Professor Mean, I need to randomize the order in which I give treatments and controls in my research study, but I don’t know how to randomize. Can you show me what to…
Aug 18, 1999
Steve Simon

R-squared

*Blog post
1999
Being updated
Linear regression
Dear Professor Mean, On my TI-83, when calculating quadratic regression, there is a number that is found called R-squared (R^2). I understand that this is the coefficient of…
Aug 18, 1999
Steve Simon

T-test

*Blog post
1999
Hypothesis testing
Dear Professor Mean, How do you analyze a t-test. I have a t-test value, and I know that I have to compare it to a t-distribution. I’m not sure how to do that.
Apr 18, 1999
Steve Simon

 

Merging files in SPSS

*Blog post
1999
Being updated
Data management
Ask Professor Mean
SPSS software
Dear Professor Mean, I get a strange error message when I try to merge two files in SPSS. What is going on? – Computing Cheryl
Jan 15, 1999
Steve Simon
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