Summary of 2-sided
values obtained from 10,000 simulation runs under a null treatment scenario. The left panel includes a histogram of the P values and the right panel is a quantile-quantile (QQ) plot of the P values against a uniform random variable. The solid line in the QQ plot is the line of equality. Such diagnostic plots - using P values generated in a scenario where the null hypothesis is true - are useful to validate a simulation program.