The Correction for Attenuation

Abstract

This article examines the statistical correction for attenuation and the controversies surrounding the procedure. Although originally developed for test construction purposes, the correction for attenuation is also used in meta-analysis and assessments of validity generalization. Since Spearman's classic article in 1904, correct use and interpretation of the correction for attenuation has been debated. The logic of the double and single correction formulae is discussed as well as the correction producing validity coefficients greater than 1.00. Three types of misapplications and misinterpretations of the correction in published literature are presented. The article concludes with arguments pertaining to the use of the correction formula, and it attempts to sharpen the focus of issues that have led to differences of opinion about its meaning and purpose.