ASA Guide to P-values

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It was 3 months before I decided to write a blogpost in response to Wasserstein, Schirm and Lazar (2019)’s editorial in The American Statistician in which they recommend that the concept of “statistical significance” be abandoned, hereafter, WSL 2019. (I titled it “Don’t Say What You don’t Mean”.) In that June 17, 2019 blogpost, pasted below, I proposed 3 “friendly amendments” to the language of that document. (There are 97 comments on that post!) The problem is that WSL 2019 presents several of the 6 principles from ASA I (the 2016 ASA statement on Statistical Significance) in a far stronger fashion so as to be inconsistent or at least in tension with some of them. I didn’t think they really meant what they said. I discussed these amendments with Ron Wasserstein, Executive Director of the ASA at the time. Had these friendly amendments been carried out, the document would not have caused as much of a problem, and people might focus more on the positive recommendations it includes about scientific integrity. The proposed ban on a key concept of statistics would still be problematic, resulting in the 2019 ASA President’s Task Force, but it would have helped the document.  At the time, it was still not known whether WSL 2019 was intended as a continuation of the 2016 ASA policy document [ASA I]. That explains why I first referred to WSL 2019 in this blogpost as ASA II. Once it was revealed that it was not official policy at all (many months later), but only the recommendations of the 3 authors, I placed a “note” after each mention of ASA II. But given it caused sufficient confusion as to result in the then ASA president (Karen Kafadar) appointing an ASA Task Force on Statistical Significance and Replicability in 2019 (see here and here), and later, a disclaimer by the authors, in this reblog I refer to it as WSL 2019. You can search this blog for other posts on the 2019 Task Force: their report is here, and the disclaimer here. Continue reading →