The debate over whether class size matters for teaching and learning is one of the most enduring-and aggressive-in education research. Teachers often insist that small classes benefit their work, but many experts argue that evidence from research shows class size has little impact on pupil outcomes, and therefore does not matter. That dominant view has informed international policymaking. In Rethinking Class Size, the lead researchers on the world’s biggest study into class size effects present a counterargument. Through detailed analysis of the complex relations involved in the classroom they reveal the mechanisms that support teachers’ experience, and they conclude that class size matters very much indeed.

Drawing on twenty years of systematic classroom observations, surveys of practitioners, detailed case studies, and extensive reviews of research, Peter Blatchford and Anthony Russell contend that common ways of researching the impact of class size are limited and sometimes misguided. While class size may have no direct effect on pupil outcomes, it can have a significant impact on interconnections within classroom processes. In describing these connections, the book opens up the everyday world of the classroom and shows that the influence of class size is felt everywhere.