Probably Overthinking It

It’s a new book that’s out, by Allen Downey

About a variety of probability “paradoxes”… but mainly how we don’t think too well about probability/stats

I am not really promoting the book, which is here:

But that he has the code for his examples, for free, here:

I don’t really need his book. (I’ll probably buy it anyway) I do want his examples & code.

He does try to head it off and say “You won’t understand these examples without the introductory text in the book!”


Anyway, those are the cat risk examples

This one is a little odd:

PCA of human measurements

In a previous post I explored the correlations between measurements in the ANSUR-II dataset, which includes 93 measurements from a sample of U.S. military personnel. I found that measurements of the head were weakly correlated with measurements from other parts of the body – and in particular the protrusion of the ears is almost entirely uncorrelated with anything else.


Meep, you’re teasing us with the conclusions about body parts without sharing some data.

I took the male only data, chose a few of the 93 measurements, and calculated correlation coefficients. I did not use PCA, but I selected the variables in the author’s principal component 6 about the head, and I added the last variable for fun: