Scholastic Aptitude Test (SAT) scores, student-reported high school grades, and scores for four other Admissions Testing Program tests were correlated with freshman grade point average for 299,794 students at 198 colleges from the enrolling classes of 1978, 1981, and 1985. The purpose of the study was to determine whether observed changes in correlations between test scores and college grades were: (1) restricted to the SAT; (2) due to changes in student subgroups; and (3) comparable at different ability levels within the freshman class. Declines were found in the correlation of freshmen grades with three of the four achievement tests examined. The data were also analyzed for students classified according to sex, ethnic group, intended major, and SAT score level. Nearly all of these demographic subgroups had the pattern of a stronger relationship of SAT scores with freshman grades for the enrolling class of 1985. A minimal decline in SAT regression weights was found for students scoring in the upper third of SAT test takers within their college. The recent decline in the relationship between SAT scores and freshman grades may be largely focused on students with SAT scores in the lower two-thirds of their respective college classes. Appendix 1 provides the yearly estimate procedure, and Appendix 2 shows the number of colleges for each pair of years. (Contains 15 tables and 7 references.) (Author/SLD)