Asserting the smallness of effects in ANOVA

Statistical inference procedures dedicated to asserting the smallness of effects are commonly used in the field of bioequivalence studies in pharmacology. They are however still virtually ignored in psychology. One possible reason is that experimental investigations generally involve complex designs for which solutions have not been developed in detail. The focus here is on the generalization of these procedures to all situations where the usual ANOVA F tests apply. Smallness confidence interval procedures, both for raw effects, such as contrasts between means and their several df extensions, and for standardized effect size measures similar to Cohen´s d and f, are considered. They are illustrated and compared with alternative Bayesian procedures previously studied. From a practical viewpoint, the computations require no more than the observed effect size, the usual F ratio, and percent points of statistical distributions. unknown publishedVersion