Although random assignment and the logical operations which flow from it, are powerful tools for hypothesis testing, there are some drawbacks. If we want to compare two treatments of anorexia, we can ...

To illustrate the importance of random assignment, I would like you to imagine we did not use random assignment in our study of treatment for COVID-19.

If participants were randomly assigned to treatments, and if the null hypothesis is true, then a given score was equally likely to fall in each of the treatments. This means that under the null ...