PREMAT: Validating a Curriculum-Based Screening Tool for Early Math Difficulties in the Context of Socioeconomic and Gender Disparities in Chile

This article presents two complementary studies examining the technical adequacy and utility of PREMAT, a CBM tool designed for screening early math difficulties in first-grade Chilean children. Study 1 evaluates reliability, predictive validity, and the factorial structure of PREMAT across three time points, as well as measurement invariance by sex and socioeconomic status (SES). Study 2 focuses on classification accuracy using ROC curve analysis. A total of 567 children (415 no-risk, 152 at-risk) from low-, middle-, and high-SES backgrounds completed five PREMAT tasks, including two underexamined screeners: Arithmetic Facts and Number Line. Confirmatory factor analyses supported a one-factor model, and partial scalar invariance was established across time, sex, and SES. Latent means revealed consistent performance gaps favoring boys and high-SES students. ROC analyses showed acceptable to excellent accuracy (AUC = .75–.89), with composite scores outperforming single tasks. Together, the findings support PREMAT as a valid and reliable screening tool for use in underrepresented educational contexts.