The United States Air Force Academy organizes its freshman class into squadrons of approximately 30 students each according to an algorithm that creates demographically balanced peer-groups. Researchers conducted a randomized evaluation to test the impact of an alternate algorithm that optimizes the performance of lower-ability students instead.
Incoming students in 2007 and 2008 were randomly assigned to either a control or treatment group. The control group squadrons were assigned using the existing algorithm. The treatment group squadrons were assigned as specially engineered peer groups. Researchers analyzed the squadron composition and academic performance of first-year students from 2001-2006 and, based on these data, generated a formula that sorted students into groups predicted to maximize the performance of the lower-ability students. The application of this formula resulted in the creation of two types of squadrons: one type composed largely of lower-ability and high-ability students only (bimodal squadron), and the other composed largely of middle-ability students (homogenous squadrons). Students remained in their squadrons for the first year.