Mistakes concerning a chance encounter between Francis Galton and John Venn

Abstract

A chance encounter at Bournemouth between Francis Galton and John Venn has lain in some obscurity because of a slip by Galton himself and a second mistake by Karl Pearson. The contact with Venn provides insight into the development of Galton's perception of statistical dispersion, his disenchantment with the notion of ‘probable error’ and adoption of population variability.

Notes

¹ I discovered Pearson's mistake whilst undertaking the research that led to my doctoral thesis (Pritchard 2005). This paper is taken from chapter 5 of the thesis.

² In the latter, John Venn stressed his father's 32-year stint as honorary secretary of the CMS, during which time the number of missionaries working for the society trebled.

³ Venn's view changed whilst revising his Logic of chance for the third edition and he came closer to the ‘degree-of-belief’ view, without altogether abandoning the frequentist view.

⁴ This is a definition that fails to draw a distinction between a ratio and the limit of a ratio. Such a distinction was drawn only in the twentieth century, originally by Richard von Mises (1919).