The Use and Impact of Adjusted R^2 Effects in Published Regression Research

Abstract

This paper empirically evaluates the reporting of adjusted effect sizes (e.g., adjusted R2, omega2) in published multiple regression studies by (a) documenting the frequency of adjusted effect reporting and interpretation, (b) identifying the types of corrected effects reported, and (c) estimating the degree of "shrinkage" present across regression analyses by using the information found in published journal articles to calculate corrected effects based on various formulae. Adjusted effects were infrequently reported in the literature, and interpretation of adjusted effects that were reported was rare.