Using retrospective data, study authors found 10 Early Colleges in 5 states that (a) operated exclusively as Early College High Schools, (b) had graduates during the study years, and (c) used and kept records of a lottery process to determine who would be offered admission to the program. A total of 2,458 students from 3 cohort years entered the identified lotteries. Students who were offered admission to Early College High Schools via the lottery formed the intervention group, while students not offered admission formed the comparison group.
Study authors reported that from 2005 to 2011, 86% of the intervention students graduated high school versus 81% of comparison students. Postsecondary enrollment was 80% for the Early College students and 71% for the comparison students. Additionally, 22% of Early College students earned a postsecondary degree during the study period, compared to 2% of comparison students. All of these differences were reported as being statistically significant.