Past and Future American Psychological Association Guidelines for Statistical Practice

We review the publication guidelines of the American Psychological Association (APA) since 1929 and document their advice for authors about statistical practice. Although the advice has been extended with each revision of the guidelines, it has largely focused on null hypothesis significance testing (NHST) to the exclusion of other statistical methods. In parallel, we review over 40 years of critiques of NHST in psychology. Until now, the critiques have had little impact on the APA guidelines. The guidelines are influential in broadly shaping statistical practice, although in some cases recommended reporting practices are not closely followed. The guidelines have an important role to play in reform of statistical practice in psychology. Following the report of the APA's Task Force on Statistical Inference, we propose that future revisions of the guidelines reflect a broader philosophy of analysis and inference, provide detailed statistical requirements for reporting research, and directly address concerns about NHST. In addition, the APA needs to develop ways to ensure that its editors succeed in their leadership role in achieving essential reform.