Published Online: 19 SEP 2008
Copyright © 2007 by John Wiley & Sons, Inc.
Wiley Encyclopedia of Clinical Trials
How to Cite
Goodman, S. N. 2008. P Value. Wiley Encyclopedia of Clinical Trials. 1–5.
- Published Online: 19 SEP 2008
The P value is the probability, under a given simple hypothesis, of the observed or a more extreme value of a test statistic. Problems discussed include that of the choice of test statistic, the relevance of alternative hypotheses, ambiguity about the sample space, and the interpretation generally. The distinction between one-sided and two-sided tests is a source of confusion. Bayesian considerations are discussed.
- significance test;
- tail area;
- null hypothesis;
- sample space;
- Bayes factor