A Bayesian Perspective on the Proposed FDA Guidelines for Adaptive Clinical Trials

The frequentist food and drug administration (FDA) has circulated a draft version of new guidelines for adaptive designs, with the explicit purpose of soliciting comments. The draft is titled “Adaptive designs for clinical trials of drugs and biologics: Guidance for industry” and you can find it here. As summarized on the FDA webpage, this draft document        …

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Bayesian Advantages for the Pragmatic Researcher: Slides from a Talk in Frankfurt

This Monday in Frankfurt I presented a keynote lecture for the 51th Kongress der Deutschen Gesellschaft fuer Psychologie. I resisted the temptation to impress upon the audience the notion that they were all Statistical Sinners for not yet having renounced the p-value. Instead I outlined five concrete Bayesian data-analysis projects that my lab had conducted in recent years. So no…

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Redefine Statistical Significance XVII: William Rozeboom Destroys the “Justify Your Own Alpha” Argument…Back in 1960

Background: the recent paper “Redefine Statistical Significance” suggested that it is prudent to treat p-values just below .05 with a grain of salt, as such p-values provide only weak evidence against the null. The counterarguments to this proposal were varied, but in most cases the central claim (that p-just-below-.05 findings are evidentially weak) was not disputed; instead, one group of…

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Redefine Statistical Significance Part XVI: The Commentary by JP de Ruiter

Across virtually all of the empirical disciplines, the single most dominant procedure for drawing conclusions from data is “compare-your-p-value-to-.05-and-declare-victory-if-it-is-lower”. Remarkably, this common strategy appears to create about as much enthusiasm as forcefully stepping in a fresh pile of dog poo. For instance, In a recent critique of the “compare-your-p-value-to-.05-and-declare-victory-if-it-is-lower” procedure, 72 researchers argued that p-just-below-.05 results are evidentially weak, and…

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Replaying the Tape of Life

In his highly influential book ‘Wonderful Life’, Harvard paleontologist Stephen Jay Gould proposed that evolution is an unpredictable process that can be characterized as “a staggeringly improbable series of events, sensible enough in retrospect and subject to rigorous explanation, but utterly unpredictable and quite unrepeatable. Wind back the tape of life to the early days of the Burgess Shale; let…

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A Bayesian Decalogue: Introduction

With apologies to Bertrand Russell. John Tukey famously stated that the collective noun for a group of statisticians is a quarrel, and I. J. Good argued that there are at least 46,656 qualitatively different interpretations of Bayesian inference (Good, 1971). With so much Bayesian quarrelling, outsiders may falsely conclude that the field is in disarray. In order to provide a…

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A 171-Year-Old Suggestion to Promote Open Science

Tl;dr In 1847, Augustus De Morgan suggested that researchers could avoid overselling their work if, every time they made a key claim, they reminded the reader (and themselves) of how confident they were in making that claim. In 1971, Eric Minturn went further and proposed that such confidence could be expressed as a wager, with beneficial side-effects: “Replication would be…

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Error Rate Schmerror Rate

“Anything is fair in love and war” — this saying also applies to the eternal struggle between frequentists (those who draw conclusions based on the performance of their procedures in repeated use) and Bayesians (those who quantify uncertainty for the case at hand). One argument that frequentists have hurled at the Bayesian camp is that “Bayesian procedures do not control…

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