When is a control chart not a control chart? (created 2007-02-06).

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 average. They look quite similar and you might be tempted to analyze both of them using a control chart. But the second example is different in subtle, but important ways and it is better analyzed using an approach called Analysis of Means (ANOM).

This webpage was originally published at the StATS website, which is currently unavailable. There is a dispute about the ownership of these pages, so I am only able to include a brief excerpt from this page.

This work is licensed under a Creative Commons Attribution 3.0 United States License. This page was written by Steve Simon and was last modified on 2008-11-15. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Analysis of means.