The "laboratory" in which the Early Admission experiment has been conducted consists of a diverse group of institutions of higher learning. They range in size from a large university such as Wisconsin (registration: 17,800), where the Scholars represented only a tiny fraction of each entering class, down to the small college of Shimer, where the student body numbers less than 150 and the Scholars were almost as numerous as their classmates. Three of the institutions—Chicago, Louisville, and Shimer—had done considerable previous experimenting with the admission of young students who had not finished high school. For the remaining nine institutions, a policy of early admission was new.

One of the participating colleges—Goucher—is restricted to women, and four—Columbia, Lafayette, Morehouse, and Yale—are restricted to men. The rest are co-educational. Two institutions—Fisk and Morehouse—have traditionally been attended by Negro students. As for control, two of the largest universities—Wisconsin and Utah—are state-operated, and another—Louisville—is municipal, while the remaining nine institutions are privately supported.

While this diversity among the participating institutions has not simplified the task of over-all interpretation of results, it has meant that the Early Admission experiment has been conducted under conditions fairly representative of American higher education as a whole.