The Only True Path

Master Stem was teaching the class about the perils of observational data when Student Leaf interrupted. "Master Stem," the student inquired, "You have taught us that randomized studies are the only true path to knowledge. So why do you now teach us about observational studies?"

Master Stem replied, "Have I been so certain about the true validity of research that uses randomization?"

Student Leaf replied, "Yes, Master Stem. You taught us that randomized studies assure us of a fair and unbiased comparison that cannot be achieved without randomization. By invoking the law of large numbers, you have shown that only randomized studies prevent bias from unknown and unmeasured covariates."

Then Master Stem replied, "Very good, Student Leaf. And this knowledge about the superiority of randomized studies, did it itself emerge from a randomized study?"

This work is licensed under a Creative Commons Attribution 3.0 United States License. It was written by Steve Simon and was last modified on 2017-06-15. Category: Teaching resources