A Table for the Rapid Determination of the Tetrachoric Correlation Coefficient

Abstract
A table is developed and presented to facilitate the computation of the Pearson Q3 (“cosine method”) estimate of the tetrachoric correlation coefficient. Data are presented concerning the accuracy of Q3 as an estimate of the tetrachoric correlation coefficient, and it is compared with the results obtainable from the Chesire, Saffir, and Thurstone tables for the same four-fold frequency tables.