Research Insights: Do Different Classroom Assignment Strategies in Middle School Matter for Student Performance?

We implemented a large-scale field experiment in 171 public schools in Mexico grouping students based on initial academic performance under two models: tracking (i.e., sorting students by initial performance) and bimodal classrooms (i.e., grouping weak and strong students together in the same classroom). Students in tracking and in bimodal classroom experienced similar average learning gains of about 0.08 of a standard deviation. The treatment effects were larger and more persistent among initially high-achieving students and no significant among low-achievers.