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Does class size matter?

New research in Elementary School Journal questions deeply held assumptions about the educational achievement gap

University of Chicago Press Journals

No more vexing problem in education exists today than the achievement gap in this country. The difference between the extremes has rightfully attracted national attention, and one of the most popular policy proposals is to reduce class size--not surprising, since benchmarks are easily measured. In his provocative article for the March 2008 issue of Elementary School Journal, "Do Small Classes Reduce the Achievement Gap between Low and High Achievers" Evidence from Project STAR", Spyros Konstantopoulos (Northwestern University) explores the hard data and finds that some of our basic assumptions about class size may be incorrect.

Konstantopoulos worked with data on mathematics and reading achievement provided by Tennessee's Project STAR (Student/Teacher Achievement Ratio), an unprecedented four-year longitudinal class-size study encompassing over 11,000 K-3 students in 79 schools. The project found, not surprisingly, that smaller class size is a better situation for the children at all achievement levels, and previous analyses saw rising achievement on average. For most advocates, parents, and policy makers, this was enough. But when Konstantopoulos dug deeper, he found that the children who are already high achievers benefited the most from the extra attention afforded by smaller classes. Low achievers also benefited from being in small classes (compared to low achievers in regular size classes), but they did not benefit not as much as high achievers. Unfortunately, he also found that the smaller classes produced higher variability in achievement which indicates that the achievement gap between low and high achievers is larger in small classes than in regular size classes, especially in kindergarten and first grade.

Do smaller classes help students" Yes...and no. Konstantopoulos finds that "although all types of students benefited from being in small classes, reductions in class size did not reduce the achievement gap between low and high achievers" He concludes by calling for more observational studies of classrooms themselves, as we still do not know how to address one of the most vexing problems--the achievement gap between students--facing educators and policy-makers, today.


Spyros Konstantopoulos is Assistant Professor of Education & Social Policy at Northwestern University.

The Elementary School Journal has served researchers, teacher educators, and practitioners in the elementary and middle school education for over one hundred years. ESJ publishes peer-reviewed articles dealing with both education theory and research and their implications for teaching practice. In addition, ESJ presents articles that relate the latest research in child development, cognitive psychology, and sociology to school learning and teaching.

Spyros Konstantopoulos "Do Small Classes Reduce the Achievement Gap between Low and High Achievers" Evidence from Project STAR" Elementary School Journal 108:4

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