The posterior probability of a null hypothesis given a statistically significant result

The posterior probability of a null hypothesis given a statistically significant result

Blog Article

When researchers carry out a null hypothesis significance test, it is tempting to assume that a statistically significant result lowers Prob(H0), the probability of the null hypothesis being true.Technically, such a statement is meaningless for various reasons: e.g., the null hypothesis does not have a probability associated with it.

However, it is possible to relax certain assumptions to compute the posterior probability Prob(H0) under repeated sampling.We show in a step-by-step guide that the intuitively appealing belief, that Prob(H0) is low when significant results have been obtained under repeated sampling, Audio Video Lead is in general incorrect and depends greatly on: (a) the prior probability of the null being true; (b) type-I error rate, (c) type-II error rate, and (d) replication of a result.Through step-by-step simulations using open-source code in the R System of Statistical Course a pied - Homme - Chaussures - Light trainer Computing, we show that uncertainty about the null hypothesis being true often remains high despite a significant result.To help the reader develop intuitions about this common misconception, we provide a Shiny app (https://danielschad.

shinyapps.io/probnull/).We expect that this tutorial will help researchers better understand and judge results from null hypothesis significance tests.