Our survey looked at enrolled students, not the number of students accepted. In some cases, college admissions offices shared the list of high schools for their freshman classes. In others, we looked at the printed "facebooks" distributed by colleges, which were either loaned to us or purchased on our behalf by students or alumni.

We worked with high schools and colleges to verify our numbers, which sometimes differed when students had been accepted to college but deferred enrollment for a year or when college facebooks offered incomplete information. In cases where the high school and college's numbers diverged, we worked with both to try to resolve the discrepancy.

We relied only on official school information, not outside sources such as Facebook.com. We omitted some universities that otherwise would have met our criteria because they either didn't print facebooks or those facebooks didn't list high-school alma maters, and the colleges wouldn't supply the data on their students independently.

Of course, college placement is only one measure of a high school's success, and varies from year to year. Many high schools emphasized to us that they strive to find the right match for each student, not the college with the most cachet.