This study compares the predictive validity of single-item and multiple-item measures of attitude toward the ad (AAd) and attitude toward the brand (ABrand), two widely measured constructs in marketing. The authors assess the ability of AAd to predict ABrand in copy tests of four print advertisements for diverse new products. They find no difference in the predictive validity between multiple-item and single-item measures. The authors conclude that for constructs consisting of a concrete singular object and a concrete attribute, such as AAd or ABrand, single-item measures should be used. The study uses bivariate correlation and multivariate regression analysis to compare the predictive validity of single-item and multiple-item measures of AAd and ABrand. The results show that single-item measures are equally valid as multiple-item measures, rejecting hypotheses that multiple-item measures capture more information or provide greater discrimination. The study also finds no evidence of common methods bias with either multiple-item or single-item measures. The findings suggest that marketing journals should accept articles with single-item measures of doubly concrete constructs.This study compares the predictive validity of single-item and multiple-item measures of attitude toward the ad (AAd) and attitude toward the brand (ABrand), two widely measured constructs in marketing. The authors assess the ability of AAd to predict ABrand in copy tests of four print advertisements for diverse new products. They find no difference in the predictive validity between multiple-item and single-item measures. The authors conclude that for constructs consisting of a concrete singular object and a concrete attribute, such as AAd or ABrand, single-item measures should be used. The study uses bivariate correlation and multivariate regression analysis to compare the predictive validity of single-item and multiple-item measures of AAd and ABrand. The results show that single-item measures are equally valid as multiple-item measures, rejecting hypotheses that multiple-item measures capture more information or provide greater discrimination. The study also finds no evidence of common methods bias with either multiple-item or single-item measures. The findings suggest that marketing journals should accept articles with single-item measures of doubly concrete constructs.