Thomson comments briefly on Thurstone’s The Vectors of the Human Mind, pointing out that Thurstone uses a theorem proved by Burt.

Thomson also refers Ledermann to articles he and Ledermann wrote for Psychometrika on boundary conditions, since this is something he wishes to write about in The Factorial Analysis of Human Ability.

He informs Ledermann that he will be taking part in a discussion at the Royal Society in London regarding The Application of Quantitative Methods to Certain Problems in Psychology.