Effects of class size and grade size on the relation between prior and subsequent achievement: A two-point panel study of 4th-to 6th-grade achievement in the Japanese language

Abstract

The "class size puzzle" refers to inconsistencies in the results of studies examining the relation between class size and academic achievement. One possible reason for this is that class size interacts with other factors. The present study examined differences in the relation between prior and subsequent achievement that have been attributed to class size, the number of classes within a grade (i.e., grade size), and the interaction of those factors, in the context of legal requirements relating to class size that affect both class size and the number of classes within a given grade. An analysis using a hierarchical linear modeling technique was conducted on 2-point panel data on achievement in the Japanese language at the start of the fourth and sixth grades, together with data on class size and the number of classes within those grades. The sample consisted of achievement data from fourth and fifth graders at 67 schools. The results suggested that for those pupils whose prior achievement had been lower, smaller class size and a larger number of classes within the grade were related to subsequent improvement in achievement more than were smaller class size and fewer classes within the grade. Discussion of these results related them to classroom quality and the frequency of collaborative efforts toward improving teaching content and teachers' methods, both of which depend on class size and the number of classes within a grade.