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February 1, 2002
Vol. 59
No. 5

The Downside to Small Class Policies

Reducing class size is popular among politicians and the public—but does research indicate that this costly initiative results in improved student achievement?

From the attention and financial support given to class size reduction by politicians and the public, one might assume that research has shown small class size to be essential to positive academic outcomes. In fiscal year 2000, the U.S. Congress allocated $1.3 billion for the class size reduction provision of the Elementary and Secondary Education Act (ESEA). During the Clinton administration, class size received a great deal of attention through proposals to pump large sums of money into efforts to increase the number of teachers in public elementary schools, thereby decreasing the ratio of students to teachers (The White House, 2000).
Proponents of class size reduction claim that small classes result in fewer discipline problems and allow teachers more time for instruction and individual attention and more flexibility in instructional strategies (Halbach, Ehrle, Zahorik, & Molnar, 2001).
Do small classes make a difference in the academic achievement of elementary school students? Are class size reduction programs uniformly positive, or does a downside exist to hiring and placing more teachers in U.S. public schools?

The California Experience

In 1995, California enacted one of the broadest-reaching laws for ensuring small classes in the early grades. Strong bipartisan approval of the class size reduction measure in the California legislature reflected broad support among constituents for reducing class sizes. The program has been wildly popular over its short lifetime, but it has faced substantial obstacles to success.
California's class size reduction program has suffered from a lack of qualified teachers to fill classrooms. More or less simultaneously, nearly all elementary schools in the state demanded more teachers, and some schools—typically suburban—attracted far more teaching applicants than did those in the inner city.
A consortium of researchers from RAND, the American Institutes for Research (AIR), Policy Analysis for California Education (PACE), EdSource, and WestEd analyzed the effects of California's class size reduction initiative and outlined two basic problems. First, K–3 classes that remained large were “concentrated in districts serving high percentages of minority, low-income, or English learner (EL) students” (Stecher & Bohrnstedt, 2000, p. x). Second, the average qualifications (that is, education, credentials, and experience) of California teachers declined during the past three years for all grade levels, but the declines were worst in elementary schools. . . .Schools serving low-income, minority, or EL students continued to have fewer well-qualified teachers than did other schools. (p. x)

Do Students Learn More in Small Classes?

Clearly, if billions of dollars are to be spent on reducing class size, tangible evidence should exist that students benefit academically from such initiatives. As yet, evidence of the efficacy of class size reduction is mixed at best.
One of the most frequently cited reports on class size is Mosteller's (1995) analysis of the Project STAR study of elementary school students in Tennessee. Mosteller found a significant difference in achievement between students in classes of 13–17 students per teacher and those in classes of 22–25.
University of Rochester economist Eric Hanushek, however, questioned Mosteller's results, noting that “the bulk of evidence . . . points to no systematic effects of class size reductions within the relevant policy range” (1999, p. 144).
In other words, no serious policy change on a large scale could decrease class size enough to make a difference.
The current class size reduction debate often ignores the fact that class sizes have been dropping slowly but steadily in the United States over the course of many years. In 1970, U.S. public schools averaged 22.3 students per teacher; by the late 1990s, however, they averaged about 17 students per teacher—a result of a combination of demographic trends and conscious policy decisions to lower pupil-teacher ratios (U.S. Census Bureau, 1999).
Local and programmatic changes in class size can be illustrative, but does research indicate that, on a national level, students in small classes experience academic achievement gains superior to those of their peers in large classes?

The National Assessment of Educational Progress

The most useful database for analyzing whether small classes lead to better academic achievement is the National Assessment of Educational Progress (NAEP). First administered in 1969, the NAEP measures the academic achievement of 4th, 8th, and 12th graders in a variety of fields, including reading, writing, mathematics, science, geography, civics, and the arts. Students take the math and reading tests alternately every two years. For example, students were assessed in reading in 1998; they were tested in math in 1996 and 2000.
The NAEP is actually two tests: a nationally administered test and a state-administered test. More than 40 states participate in the separate state samples used to gauge achievement within those jurisdictions.
In addition to test scores in the subject area, the NAEP includes an assortment of background information on the students taking the exam, their main subject-area teacher, and their school administrator. Background information includes students' television viewing habits, students' computer usage at home and at school, teacher tenure and certification, family socio-economic status, basic demographics, and school characteristics. By including this information in their assessment of the NAEP data, researchers can gain insight into the factors that might explain differences in NAEP scores found among students.

Results from the Center for Data Analysis

A study from the Center for Data Analysis at the Heritage Foundation examined the 1998 NAEP national reading data to determine whether students in small classes achieve better than students in large classes (Johnson, 2000). Researchers assessed students' academic achievement in reading by analyzing assessment scores as well as six factors from the background information collected by the NAEP: class size, race and ethnicity, parents' education attainment, the availability of reading materials in the home, free or reduced-price lunch participation, and gender.
Class size. The amount of time that a teacher can spend with each student appears to be important in the learning process. To address class size, the Center for Data Analysis study compared students in small classes (those with 20 or fewer students per teacher) with students in large classes (at least 31 students per teacher).
Race and ethnicity. Because significant differences exist in academic achievement among ethnic groups, the variables of race and ethnicity were included in the analysis.
Parents' education. Research indicates that the education attainment of a child's parents is a good predictor of that child's academic achievement. Because the education level of one parent is often highly correlated with that of the other parent, only a single variable was included in the analysis.
The availability of reading materials in the home. The presence of books, magazines, encyclopedias, and newspapers generally indicates a dedication to learning in the household. Researchers have determined that these reading materials are important aspects of the home environment (Coleman, Hoffer, & Kilgore, 1982). Essentially, the presence of such reading materials in the home is correlated with higher student achievement. The analysis thus included a variable controlling for the number of these four types of reading materials found at home.
Free and reduced-price lunch participation. Income is often a key predictor of academic achievement because low-income families seldom have the resources to purchase extra study materials or tutorial classes that may help their children perform better in school. Although the NAEP does not collect data on household income, it does collect data on participation in the free and reduced-price school lunch program.
Gender. Although data on male-female achievement gaps are inconsistent, empirical research suggests that girls tend to perform better in reading and writing subjects, whereas boys perform better in more analytical subjects such as math and science.
After controlling for all these factors, researchers found that the difference in reading achievement on the 1998 NAEP reading assessment between students in small classes and students in large classes was statistically insignificant. That is, across the United States, students in small classes did no better on average than those in large classes, assuming otherwise identical circumstances.
Such results should give policymakers pause and provoke them to consider whether the rush to hire more teachers is worth the cost and is in the best interest of students. In terms of raising achievement, reducing class size does not guarantee success.
When Irwin Kurz became the principal of Public School 161 in Brooklyn, New York, well over a decade ago, the school's test scores ranked in the bottom 25th percentile of schools in Brooklyn's 17th District. Today, P.S. 161 ranks as the best school in the district and 40th of 674 elementary schools in New York City, even though a majority of its students are poor. The pupil-teacher ratio at P.S. 161 is 35 to 1, but the teachers make neither class size, nor poverty, nor anything else an excuse for poor performance. As Kurz likes to say, “better to have one good teacher than two crummy teachers any day.”

Coleman, J., Hoffer, T., & Kilgore, S. (1982). High school achievement. New York: BasicBooks.

Halbach, A., Ehrle, K., Zahorik, J., & Molnar, A. (2001, March). Class size reduction: From promise to practice. Educational Leadership, 58(6), 32–35.

Hanushek, E. (1999). Some findings from an independent investigation of the Tennessee STAR experiment and from other investigations of class size effects. Educational Evaluation & Policy Analysis, 21(2), 143–164.

Johnson, K. (2000, June 9). Do small classes influence academic achievement? What the National Assessment of Educational Progress shows (CDA Report No. 00-07). Washington, DC: Heritage Foundation.

Mosteller, F. (1995). The Tennessee study of class size in the early school grades. The Future of Children, 5(2), 113–127.

Stecher, B., & Bohrnstedt, G. (Eds.). (2000). Class size reduction in California: The 1998–99 evaluation findings. Sacramento: California Department of Education.

U.S. Census Bureau. (1999). Statistical abstract of the United States. Washington, DC: Government Printing Office.

The White House. (2000, May 4). President Clinton highlights education reform agenda with roundtable on what works [Press release].

Kirk A. Johnson has been a contributor to Educational Leadership.

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