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Journal Issue: Financing Schools Volume 7 Number 3 Winter 1997

Eugene M. Lewit Linda Schuurmann Baker


Having fewer children in a class is attractive to both parents and teachers. One recent national poll found that 70% of adults believe that reducing class size would result in big improvements in public schools.1 Fewer than 10% believed that it would make no improvement at all. A 1997 Education Week survey found that 83% of teachers and 60% of principals agree that class size in elementary schools should not exceed 17 students, compared with a national average of 25 students per class.2 Teachers feel that smaller classes encourage increased student-teacher interaction, allow for more thorough evaluation of students, and promote greater teaching flexibility.3 However, because of the additional teachers and facilities required, reducing class size is costly. In California, for example, school districts claimed nearly $1 billion in state funds for class size reduction in 1996–97 alone.4

Recent publicity and legislative action in several states have fueled interest in smaller classes, particularly in the lower grades. Although research and debate on class size are not new, some of the increased attention comes from an evaluation of a Tennessee demonstration project. The study found that students in grades K–3 did significantly better on achievement tests when they were in classrooms with 13 to 17 students per teacher than when they were in standard-size classes (22 to 25 students) or in standard classes with a teacher and an aide.5 Children from the smaller classes continued to perform better than children from the larger classes, even in subsequent years when all children were in standard-size classes. The value of class size reduction is still being debated, however, because of the high resource costs of widespread efforts to reduce class size and uncertainty as to whether results comparable to those achieved in Tennessee can be replicated on a large scale.6 For reasons of space, this article does not review the literature on the effects of class size reductions on student achievement.7

When class size reduction is a policy goal, measuring class size consistently is important. Staffing decisions play a major role in class size because the administrative and instructional relationships between teachers and pupils result in part from the amount and type of staff hired by a school district. There are several ways that the relationship between the number of students and staff can be measured, and the statistic chosen can determine whether schools faced with a mandate to decrease class size add teachers, build classrooms, or reassign existing staff and space. This Child Indicators article examines the measurement of class size and a related measure, the pupil-teacher ratio. It also looks at variations across states in the number of students per classroom and long-term trends in class size and pupil-teacher ratios.

This article finds that pupil-teacher ratios are consistently lower than average class size because class size statistics do not reflect the use of specialized teachers or teachers who work in multiple classrooms. Because the utilization of school facilities is not included in either statistic, class size and pupil-teacher ratios do not provide any information about the adequacy of the physical environment for education. Moreover, averages of either statistic do not provide information about the range of classes of different sizes within a state, district, or school. Class size varies widely within states, and average class size in a state is not a good predictor of the prevalence of large classes in that state. Despite the differences between the two statistics, over the long term the trend has been toward both smaller classes and lower pupil-teacher ratios.