Stony Brook, N.Y.

FOR some years now, many elite American colleges have been downgrading the role of standardized tests like the SAT in deciding which applicants are admitted, or have even discarded their use altogether. While some institutions justify this move primarily as a way to enroll a more diverse group of students, an increasing number claim that the SAT is a poor predictor of academic success in college, especially compared with high school grade-point averages.

Are they correct? To get an answer, we need to first decide on a good measure of “academic success.” Given inconsistent grading standards for college courses, the most easily comparable metric is the graduation rate. Students’ families and society both want college entrants to graduate, and we all know that having a college degree translates into higher income. Further, graduation rates among students and institutions vary much more widely than do college grades, making them a clearer indicator of how students are faring.

So, here is the question: do SATs predict graduation rates more accurately than high school grade-point averages? If we look merely at studies that statistically correlate SAT scores and high school grades with graduation rates, we find that, indeed, the two standards are roughly equivalent, meaning that the better that applicants do on either of these indicators the more likely they are to graduate from college. However, since students with high SAT scores tend to have better high school grade-point averages, this data doesn’t tell us which of the indicators  independent of the other  is a better predictor of college success.

Instead, we need to look at the two factors separately. And we can, thanks to the recent experience of the State University of New York, America’s largest comprehensive university system, where I was provost from 1997 to 2006. SUNY is blessed with many different types of campuses, mirroring most of the collegiate options (other than small elite private institutions) that characterize contemporary higher education. The university also collects a gold mine of student data, including statistics on pre-admission academic profiles and graduation rates.