P-value

A p-value is the probability, computed under a null hypothesis, of obtaining a test statistic at least as unfavorable to that hypothesis as the observed value.

A random variable $P\in [0,1]$ is super-uniform when $\mathbb{P}(P\le \alpha )\le \alpha$ for every $\alpha \in [0,1]$. A valid p-value is super-uniform under its null hypothesis.