Class size: what research says and what it means for state policy
Class size is one variable in American education that research confirms has a positive influence student learning and was then taken to scale across the nation. Unfortunately, the results when applied at scale have not achieved the results expected in the initial studies.
Chingos, M. M., & Whitehurst, G. J. (2011). Class size: what research says and what it means for state policy. Brookings Institute. May, 11.