A machine method for computing the biserial correlation coefficient in item validation

A method for computing the biserial correlation coefficients with the aid of punch card equipment is oultined. A numerical example and a work sheet layout is included in the presentation.This method was developed by Dr. Elmer B. Royer prior to his untimely death on April 3, 1939. It has been prepared for publication by some of his former associates, not only as a contribution to science but also as a tribute to the memory of a true scientist.