title: Principles: when there should be no difference--how to fail to reject the null hypothesis.
abstract: It is common to perform experiments in which a 'success' is claimed when the null hypothesis is discarded. However, there is a category of experiment that has become important in which a success is when the null hypothesis is not rejected. Failing to discard the null hypothesis is different from proving it to be valid, a distinction that is particularly important in experiments in which any inadequacy of experimental design or implementation enhances the likelihood of a success. The appropriate analysis of such experiments tests for evidence of the validity of the null hypothesis rather than simply failing to find evidence against it.
authors.affiliation: Department of Pharmacology, University of Melbourne, Parkville, Victoria 3010, Australia. michaell@unimelb.edu.au
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lew
mesh_terms: D016001:Confidence Intervals; D006801:Humans; D009010:Monte Carlo Method; D010600:Pharmacology / Q000379:methods / Q000639:trends*; D015203:Reproducibility of Results; D012107:Research Design