Redefine Statistical Significance Part XXI: Edgeworth Proposed the .005 Criterion Back in 1885

The statistical significance test was not invented by Ronald Fisher. The key idea was already laid out by Francis Ysidro Edgeworth (1845-1926), whose 1885 article “Methods of statistics” is quite explicit about the purpose, design, and interpretation of the significance test. As summarized by Kennedy-Shaffer: In 1885, Francis Ysidro Edgeworth provided a more formal mathematical underpinning for the significance test…

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A Geometric Intuition for the Logarithm

The logarithm is a key concept in mathematics and statistics. Most students will be introduced to the logarithm as the function that is the inverse of exponentiation, or the function that turns multiplication into addition. But without a good intuition of what the logarithm actually is, students can struggle to remember how to compute the logarithm of base r for…

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From P-values to Bayes Factors with eJAB

This post is a teaser for Velidi, P., Wei, Z., Kalaria, S. N., Liu, Y., Laumont, C. M., Nelson, B. H., & Nathoo, F. S. (2025). Generalized Jeffreys’s approximate objective Bayes factor: Model-selection consistency, finite-sample accuracy, and statistical evidence in 71,126 clinical trial findings. ArXiv preprint:2510.10358. Abstract “Concerns about the misuse and misinterpretation of p-values and statistical significance have motivated…

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“The idea is brilliant and relevant”

A few months ago I submitted a project on open-science for the so-called OSCARS Open Call. Today I received a three-sentence evaluation. The first sentence of the feedback started as follows: “The idea is brilliant and relevant” (and from there it did not go downhill much). Scores on the various dimensions deemed “brilliant and relevant” were 2, 2, 2, 1.5,…

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A Chess Scandal Revisited II – Kramnik Responds

Background: Former world chess champion Vladimir Kramnik has argued that several win streaks of Hikaru Nakamura on chess.com are unusually long. Can we analyze these streaks to amass statistical evidence that something fishy is going on? In last week’s blogpost, I argued that the likelihood principle does not license the selection of a particular streak from a longer time series. It…

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A Chess Scandal Revisited – Why Nakamura is Right About Cherry-Picking

Recently I was attended to a paper by Maharaj, Polson, and Sokolov, in which they provided a statistical analysis of a chess cheating allegation. Their abstract: We provide a statistical analysis of the recent controversy between Vladimir Kramnik (ex chess world champion) and Hikaru Nakamura. Hikaru Nakamura is a chess prodigy and a five-time United States chess champion. Kramnik called…

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Sir Harold Jeffreys Graces the Cover of “De Psycholoog”

In a recent blogpost I introduced Marlijn Bouwman‘s painting of Sir Harold Jeffreys (1891–1989), godfather of Bayesian inference. The painting is available under a CC-BY license (and available from the artwork library on this site). This very painting now forms the cover of De Psycholoog, a Dutch magazine devoted to psychological science and insights relevant for psychological practice. Here is…

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The Hypothesis-Testing Philosophy of Harold Jeffreys Expressed As a 13-Word Slogan

[Featured image taken from a painting by Marlijn Bouwman under a CC-BY license (and available from the artwork library on this site)] In the 1930s, the polymath Harold Jeffreys developed a general Bayesian philosophy on hypothesis testing. Essentially, Jeffreys wanted to formalize the idea of scientific caution in statistical reasoning. Jeffreys argued that “variation must be taken as random until…

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