A Graphical Method for the Rapid Calculation of Biserial and Point Biserial Correlation in Test Research

Abstract

A description is given of a diagram (available separately) for computing biserial or point biserial correlation coefficients. The diagram is maximally useful where large numbers of coefficients are to be calculated in test item analysis. The diagram is entered with the mean criterion score of the group passing the item and the proportion of correct answers to the item.