Optimal Context Size in Elementary Schools: Disentangling the Effects of Class Size and School Size

Young children's learning—and how their learning is distributed by social background—may be influenced by the structural and organizational properties of their school. This study focuses on one important structural dimension of these educational contexts: size. Over the past several decades, various elements of the size of educational contexts have become a major focus of researchers, politicians, and corporate leaders. Billions of public and private dollars have been invested in reforms to reduce the size and scope of both classrooms and schools. Unlike many educational reform initiatives, these downsizing efforts have found support from virtually every quarter. A united front of stakeholders has coalesced behind the notion that "smaller is better." Although size-reduction policies are well intentioned, their effectiveness is unclear, and some efforts have produced unintended and even undesirable consequences. Moreover, their cost-effectiveness has seldom been considered.

Based on results from the famous Tennessee class-size experiment, California invested billions of dollars encouraging its schools to limit classes in the early grades to no more than twenty students. Quite recently, the push to reduce the size of high schools has been accompanied by enormous financial support from foundations and the federal government in an effort to encourage schools-within-schools, small learning communities, and small stand-alone schools. Curiously, these important policy initiatives—reduced class size and reduced school size—have not been simultaneously considered within elementary school contexts. However, the effects of class size may be a function of school size, the effects of school size may be a function of class size, or both. The lack of research that simultaneously considers these potentially related elements of size is somewhat surprising.

Despite the groundswell of public support for smaller educational settings, the empirical base regarding the confounding effects of various components of elementary school size remains quite sparse, particularly if only methodologically sound studies are considered. Moreover, crafting size-reduction polices that faithfully reproduce the findings of experimental and quasi-experimental studies is a challenging task. In short, efforts to reduce various elements of size in elementary schools may be an instance where policy is far in front of research.

Background

Determining how the size of educational contexts may influence student outcomes can be conceptualized and measured at multiple levels. Decisions regarding the appropriate unit of analysis are important, as each level may uniquely influence student learning. It seems logical to assume that the social and structural consequences of size would be strongest where they most directly affect the daily activities of teaching and learning. For example, at the elementary school level, a focus on class size seems most reasonable. Unlike high school students, elementary school students spend more time in a single classroom. However, non- and quasi-experimental studies of elementary school class size rarely account for school size—clearly a problem, as class size may be a function of school size. Moreover, as most high schools contain the same grades (nine through twelve), examining the effects of school size on student outcomes in those contexts seems quite appropriate. Conversely, the grade spans that elementary schools include vary widely, with K–3, K–6, and K–8 schools all relatively common. If elementary schools contain fewer grades (K–3, for example), each grade is likely to include more students and classes. Thus grade size may be an additional element of context size in elementary schools.

Unfortunately, the research on these separate (yet related) elements of elementary school size is generally quite weak. Apart from the recent class-size experiments in Tennessee and Wisconsin, research in this area generally employs small and nonrepresentative samples, relies on cross-sectional data, and suffers from numerous other methodological limitations. Moreover, the theoretical justifications behind these studies often rest on literature reviews. One strange result is a circular chain, wherein literature reviews often cite other literature reviews rather than solid empirical studies. In one sense this is understandable, given the scarcity of high-quality research on the topic. Our review focuses on class size in elementary schools, as the research...