[gradschoolfail]

For pedagogues and practitioners alike: there is a subtle connection between Simpson’s paradox and the wild geometry of relative entropy. This might be partly why effect sizes are also contentious.

Besides Ellenberg’s mind-altering discussion of that link[1], see hints on the second page of:

https://www.qeios.com/read/XB1N2A/pdf

[1] "[the point of Simpson’s paradox] isn't really to tell us which viewpoint to take but to insist that we keep both the parts and the whole in mind at once."

Ellenberg, from Shape: The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else (2021)