Simple formula aids for understanding the joint action of two predictors

Abstract

"It was demonstrated that the ratio of any two fixed validity coefficients will locate a value for the intercorrelation term in the two-predictor, multiple correlation formula such that the variable having the lower validity will contribute nothing to the variable having the higher validity. The resulting multiple correlation is thereby a minimum. A second formula is presented that determines two intercorrelation values for any fixed pair of validity coefficients which will result in a multiple correlation of 1.00. This second formula does not hold when both validity coefficients are exactly zero, and is restricted to determination of a single intercorrelation value when the two validity coefficients are exactly equal and not zero. From Psyc Abstracts 36:05:5AG85M. (PsycInfo Database Record (c) 2025 APA, all rights reserved)