Moderating effects and differential reliability and validity

Abstract

Classic psychometric theory holds that errors of measurement and of prediction are of the same magnitude for all individuals. Interactive effects are not recognized, and the psychological structure of all individuals is taken to be the same. To increase reliability and validity of measurement, then, attention is entirely focused on improvement of measuring devices. However, a substantial body of evidence indicates there are systematic individual differences in error, and in the importance a given trait has in determining a particular performance. Reliability and validity of measurement can be increased by the use of moderator variables which predict individual differences in error and in the importance of traits. (16 ref.) (PsycInfo Database Record (c) 2025 APA, all rights reserved)