Are validity coefficients understated due to correctable defects in the GPA?

The predictive validity of preadmissions measures such as standardized test scores and high school grades may be understated because of correctable defects in both the freshman year and cumulative grade point average (GPA). Measurement error in the criterion artificially depresses the size of observed validity coefficients. A study was conducted using item response theory (IRT) to develop a more reliable measure of performance, called an IRT-based GPA, and tested in a predictive validity study using data from Stanford University. Results indicate increased predictability when the IRT-based GPA is compared with the usual GPA.This article is based, in part, on the doctoral dissertation of the author, which was completed at the School of Education at Stanford University.