Triserial r—a neglected statistic

Abstract

An empirical study is reported comparing biserial r and triserial r for 100 samples from each of three populations (product-moment r's of .28, .66, and .91). The empirical standard deviations of triserial r were consistently lower than the standard errors of biserial r. Furthermore, "… the simple formula can be safely used when the high and low groups do not differ by more than .10." (PsycInfo Database Record (c) 2025 APA, all rights reserved)