Questions and Answers: Reproducibility and a Stricter Threshold for Statistical Significance

By Justin Esarey

[Update 12/2/2018 at 10:45 AM ET: A corrigendum to answers from Justin Esarey has been published.]

“Redefine statistical significance,” a paper recently published in Nature Human Behavior (Benjamin et al., 2017) generated a substantial amount of discussion in methodological circles. This paper proposes to lower the \alpha threshold for statistical significance from the conventional level of 0.05 to a new, more stringent level of 0.005 and to apply this threshold specifically to newly discovered relationships (i.e., relationships that have not yet been demonstrated in multiple studies). This proposal touched off a debate about the effect null hypothesis significance testing (NHST) has on published work in the social and behavioral sciences in which many statisticians and social scientists have participated. Some have proposed alternative reforms that they believe will be more effective at improving the replicability of published results.

To facilitate further discussion of these proposals—and perhaps to begin to develop an actionable plan for reform—the International Methods Colloquium (IMC) hosted a panel discussion on “reproducibility and a stricter threshold for statistical significance” on October 27, 2017. The one-hour discussion included six panelists and over 240 attendees, with each panelist giving a brief initial statement concerning the proposal to “redefine statistical significance” and the remainder of the time being devoted to questions and answers from the audience. The event was recorded and can be viewed online for free at the International Methods Colloquium website.

Unfortunately, the IMC’s time limit of one hour prevented many audience members from asking their questions and having a chance to hear our panelists respond. Panelists and audience members alike agreed that the time limit was not adequate to fully explore all the issues raised by Benjamin et al. (2017). Consequently, questions that were not answered during the presentation were forwarded to all panelists, who were given a chance to respond.

The questions and answers, both minimally edited for clarity, are presented in this article. The full series of questions and answers (and this introduction) are embedded in the PDF below.

2017-12-6_imc-pvalue-qanda.pdf201 KB