The SAT has proven to be an important predictor of success in college. Its validity as a predictor of success has been demonstrated through hundreds of validity studies. These validity studies consistently find that high school grades and SAT scores together are substantial and significant predictors of achievement in college. In these studies, although high school grades typically are slightly better predictors of achievement, SAT scores add significantly to the prediction. These findings tend to hold for all subgroups of students and for all types of measures freshman grades, course grades, cumulative grades, and measures of persistence.