The persistence of underpowered studies in psychological research: causes, consequences, and remedies.
Underpowered studies persist in the psychological literature. This article examines reasons for their persistence and the effects on efforts to create a cumulative science. The "curse of multiplicities" plays a central role in the presentation. Most psychologists realize that testing multiple hypotheses in a single study affects the Type I error rate, but corresponding implications for power have largely been ignored. The presence of multiple hypothesis tests leads to 3 different conceptualizations of power. Implications of these 3 conceptualizations are discussed from the perspective of the individual researcher and from the perspective of developing a coherent literature. Supplementing significance tests with effect size measures and confidence intervals is shown to address some but not necessarily all problems associated with multiple testing.
Maxwell
Scott E
SE
Department of Psychology, University of Notre Dame, Notre Dame, IN 46556, USA. smaxwell@nd.edu
D006801:Humans; D011584:Psychology; D012106:Research / Q000458:organization & administration* / Q000592:standards