Do GRE scores help predict getting a physics Ph.D.? A comment on a paper by Miller et al.

A recent paper in Science Advances by Miller et al. concludes that Graduate Record Examinations (GREs) do not help predict whether physics graduate students will get Ph.D.’s. Here, I argue that the presented analyses reflect collider-like stratification bias, variance inflation by collinearity and range restriction, omission of parts of a needed correlation matrix, a peculiar choice of null hypothesis on subsamples, blurring the distinction between failure to reject a null and accepting a null, and an unusual procedure that inflates the confidence intervals in a figure. Release of results of a model that leaves out stratification by the rank of the graduate program would fix many of the problems.