School size is a factor in student achievement

iStock_000002424978XSmallEditor’s Note: Chicago’s elementary schools are somewhat unusual in that most are K-8 schools. Research has shown that keeping students longer in the same school setting has educational benefits. Students who attend K-12 schools tend to perform better than those in K-8, who, in turn, perform better than those who change schools more often.

A large-scale study in Chicago found that students learn more in small schools. In elementary schools with fewer than 400 students, teachers say they are more likely to take responsibility for students’ learning, and students in these schools show greater gains on standardized math tests. Researchers Valerie E. Lee, University of Michigan, and Susanna Loeb, Stanford University, analyzed data provided by the Consortium on Chicago School Research for 5,000 teachers and 23,000 sixth- and eighth-grade students in 264 K-8 schools.

Research on School Size

Almost all previous research related to school size has been carried out in high schools and has focused on how size affects students. Achievement gains in both math and reading were largest in high schools with 600-900 students. Schools enrolling more than 2,000 students scored lower than all smaller schools. Small schools were also more equitable than larger schools because the more constrained curriculum in many small high schools meant that all students take the same academic courses, reducing differences often seen in larger schools along racial and socioeconomic lines. Researchers suggest that as schools get larger, they become both more specialized and more impersonal. Teachers know individual students less well and have fewer cooperative relationships with other teachers. As schools get bigger, teachers’ sense of responsibility for students’ learning is weakened. Teachers in large schools are more likely to believe that ability or home environment is responsible for students’ achievement.

Schools are becoming larger. School consolidation at the high-school level has been going on for more than 30 years, as a way to cut costs and offer a broader curriculum. These researchers report, however, that increased costs for transportation and expanded administrative staffs have kept savings from materializing. Large schools do offer more diverse and specialized coursework. But the unintended result of this is increased social stratification that has debilitating consequences for students in lower tracks.

Teachers’ attitudes about their work and about their students’ ability are important factors that influence students’ achievement. Research demonstrates that when teachers hold high expectations for their students, students are more engaged in learning. And when teachers feel personally responsible for students, students learn more. Achievement is higher in schools where the majority of teachers feel responsible for the success or failure of their teaching. Students achieve less in schools where teachers believe impediments to learning are outside their control, such as students’ lack of ability or motivation, or students’ impoverished backgrounds.

Study of Chicago’s Elementary Schools

Lee and Loeb investigated the impact of school size in Chicago, with its high proportions of poor and minority students. They studied how size affected the math achievement of all students in the sixth and eighth grades and how it affected teachers’ attitudes about their students. They asked three questions:

1. Is school size related to the willingness of teachers to assume responsibility for students’ academic and social development?

2. Is this sense of collective responsibility related to student achievement?

3. Does school size have a direct effect on student achievement, once collective responsibility and student demographics are taken into account?

Teachers’ and students’ background characteristics (gender, race, and socioeconomic status) were taken into account in the analysis, as were the effects of students’ mobility and retention. Eighty-two percent of the students in this study were low-income and 75 percent were minority students. Students were tested annually on the portions of the Iowa Test of Basic Skills that measure students’ understanding of the number system, mathematics terms and concepts, estimation, problem solving and data interpretation.

Schools were divided into three sizes: small (fewer than 400 students), medium (400 to 750 students), and large (more than 750 students). Less than 10 percent of the schools were small, while 36 percent were large and more than half were medium-size.

Better math scores at small schools

While the most important predictor of a student’s mathematics achievement score was his previous score, mathematics achievement scores differed considerably between schools of different sizes. Lee and Loeb report that small schools in this sample had a somewhat more advantaged population. Smaller schools had fewer poor and minority students and lower rates of mobility and retention. However, when these factors were controlled, students in small schools still learned considerably more mathematics than similar students in medium-size schools.

Factor analysis revealed that school size had both direct and indirect effects on student learning. School size was strongly associated with teachers’ attitudes about collective responsibility, the degree of collective responsibility was associated with learning; and school size was associated with learning.


This study demonstrates that in Chicago’s elementary schools size matters. Findings are consistent and show that small elementary schools work better in terms of mathematics achievement. In schools with fewer than 400 students, teachers report that they and their colleagues believe they are responsible for their students’ learning. Lee and Loeb say that teachers in small schools interact more often with fewer students, know these students better, and are more concerned about their failures. They provide more help, take responsibility for discipline, and invest more fully in the whole school. In these small schools, teachers and students enjoy more intimate and personal social relations. These researchers believe that the quality and character of these relationships are important factors in students’ learning.This study demonstrates that school size is important for students’ learning. Lee and Loeb conclude that it provides empirical support for a move toward small elementary schools, particularly in disadvantaged urban areas.

“School Size in Chicago Elementary Schools: Effects on Teachers’ Attitudes and Students’ Achievement” American Educational Research Journal Volume 37, Number 1, Spring 2000 Pp. 3-31

Published in ERN December/January 2001 Volume 14 Number 1

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