Monthly Archives: October 2022

S. Senn: Lauding Lord (Guest Post)



Stephen Senn
Consultant Statistician
Edinburgh, Scotland

A Diet of Terms

A large university is interested in investigating the effects on the students of the diet provided in the university dining halls and any sex difference in these effects. Various types of data are gathered. In particular, the weight of each student at the time of his arrival in September and their weight the following June are recorded.(P304)

This is how Frederic Lord (1912-2000) introduced the paradox (1) that now bears his name. It is justly famous (or notorious). However, the addition of sex as a factor adds nothing to the essence of the paradox and (in my opinion) merely confuses the issue. Furthermore, studying the effect of diet needs some sort of control. Therefore, I shall consider the paradox in the purer form proposed by Wainer and Brown (2), which was subtly modified by Pearl and Mackenzie in The Book of Why (3) (See pp212-217). Continue reading

Categories: Lord's paradox, S. Senn | 8 Comments

Multiplicity, Data-Dredging, and Error Control Symposium at PSA 2022: Mayo, Thornton, Glymour, Mayo-Wilson, Berger


Some claim that no one attends Sunday morning (9am) sessions at the Philosophy of Science Association. But if you’re attending the PSA (in Pittsburgh), we hope you’ll falsify this supposition and come to hear us (Mayo, Thornton, Glymour, Mayo-Wilson, Berger) wrestle with some rival views on the trenchant problems of multiplicity, data-dredging, and error control. Coffee and donuts to all who show up.

Multiplicity, Data-Dredging, and Error Control
November 13, 9:00 – 11:45 AM
(link to symposium on PSA website)

Speakers: Continue reading

Categories: Announcement, PSA | Leave a comment

Where should stat activists go from here? (part (i))


From what standpoint should we approach the statistics wars? That’s the question from which I launched my presentation at the Statistics Wars and Their Casualties workshop ( In my view, it should be, not from the standpoint of technical disputes, but from the non-technical standpoint of the skeptical consumer of statistics (see my slides here). What should we do now as regards the controversies and conundrums growing out of the statistics wars? We should not leave off the discussions of our workshop without at least sketching a future program for answering this question. We still have 2 more sessions, December 1 and 8, but I want to prepare us for the final discussions which should look beyond a single workshop. (The slides and videos from the presenters in Sessions 1 and 2 can be found here.)

I will consider three, interrelated, responsibilities and tasks that we can undertake as statistical activist citizens. In so doing I will refer to presentations from the workshop, limiting myself to session #1. (I will add more examples in part (ii) of this post.) Continue reading

Categories: Error Statistics, significance tests, stat wars and their casualties | Leave a comment

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