Reducing the size of classes – particularly in the primary grades – is a popular reform idea embraced by teachers, administrators, parents and a growing number of policymakers. Classes with 25 students or more are simply too large, many people say, to provide the kind of individualized attention students need to succeed.

Since the mid-1980s, 20 states have launched initiatives aimed at reducing class size, mostly in grades K-3. States spent an estimated $2.3 billion on such efforts in the 1999-2000 school year, according to the ERIC Clearinghouse on Educational Management. In addition, the federal government’s Class Size Reduction Program, established in 1998, is providing roughly $1.2 billion a year to help states hire and train new teachers as part of an overall goal of lowering class size in the early grades to no more than 18 students nationwide.

For the most part, research tends to support the notion that smaller classes in the early grades promote effective teaching and learning. While not all studies on the subject have shown that students learn more in smaller settings, most studies have found benefits.

But some states and districts are finding that class-size reduction is both difficult and extraordinarily expensive. For example, California’s four-year-old effort to reduce classes to no more than 20 students in the lower grades is costing more than $1.5 billion a year and has led to critical shortages of qualified teachers, particularly in schools serving poor and minority students. In Detroit, where the school district last year implemented a $13.2 million program to reduce primary-grade class sizes, progress has been hampered by shortages of both classrooms and teachers.

Some policymakers and researchers believe the costs of reducing class size are prohibitively high, and that the money would be better spent supporting other types of reform. If districts hire the most qualified teachers and support them with ongoing professional development, class size becomes an irrelevant issue, say some critics of the push toward smaller classes.

Clearly, reducing class size is a significant means of improving student achievement but high academic standards, a challenging curriculum, safe and orderly classrooms, and qualified teachers are no less significant in the arsenal of solid, research-proven reforms. When smaller class size is pursued in conjunction with such reforms, the combined impact on student achievement is far greater than any strategy by itself.