The fifth edition of the APA Publication Manual:: Why its statistics recommendations are so controversial

The fifth edition of the Publication Manual of the American Psychological Association (APA) draws on recommendations for improving statistical practices made by the APA Task Force on Statistical Inference (TFSI). The manual now acknowledges the controversy over null hypothesis significance testing (NHST) and includes both a stronger recommendation to report effect sizes and a new recommendation to report confidence intervals. Drawing on interviews with some critics and other interested parties, the present review identifies a number of deficiencies in the new manual. These include lack of follow-through with appropriate explanations and examples of how to report statistics that are now recommended. At this stage, the discipline would be well served by a response to these criticisms and a debate over needed modifications.