Problem with p values: why p values do not tell you if your treatment is likely to work

Why are p-values controversial?

While it is often argued that a p-value is a probability; see Wasserstein & Lazar (2016), we argue that a p-value is not defined as a probability. A p-value is a bijection of the sufficient statistic for a given test which maps to the same scale as the type I error probability. As such, the use of p-values in a test should be no more a source of controversy than the use of a sufficient statisti...

What the P values really tell us

Received September 12, 2017. Accepted September 17, 2017. Correspondence to: Francis Sahngun Nahm Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82 Gumi-ro, 173 Beon-gil, Bundang-gu, Seongnam 13620, Korea Tel: +82-31-787-7499, Fax: +82-31-787-4063, E-mail: [email protected] This is an open-access article distributed under the terms of the Creative ...

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P Values are not Error Probabilities

Confusion surrounding the reporting and interpretation of results of classical statistical tests is widespread among applied researchers. The confusion stems from the fact that most of these researchers are unaware of the historical development of classical statistical testing methods, and the mathematical and philosophical principles underlying them. Moreover, researchers erroneously believe t...

A farewell to P-values?

A recent paper in the medical literature by Sterne and Davey-Smith has focused attention on some of the problems of interpretation of significance/hypothesis tests; in particular, the meaning and status of P-values associated with these tests. What were these concerns: that the division of results into “significant” and “nonsignificant” according to a P-value = 0.05 was arbitrary and not in acc...