Neyman-Pearson lemma

A lemma asserting that in the problem of statistically testing a simple hypothesis against a simple alternative the likelihood-ratio test is a most-powerful test among all statistical tests having one and the same given significance level. It was proved by J. Neyman and E.S. Pearson [1]. It is often called the fundamental lemma of mathematical statistics. See also Statistical hypotheses, verification of.

References

[1]	J. Neyman, E.S. Pearson, "On the problem of the most efficient tests of statistical hypotheses" Philos. Trans. Roy. Soc. London Ser. A. , 231 (1933) pp. 289–337
[2]	E.L. Lehmann, "Statistical hypotheses testing" , Wiley (1978)