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Class Size

This version was published in 2004. An updated version from 2011 is available.

In recent years, reducing class size has gained increased prominence as a school-improvement strategy. Some 40 states now have class-size-reduction initiatives in place, and federal money is available for such efforts as well. The teachers' unions, meanwhile, routinely tout class-size reduction as an alternative to private school vouchers.

Such goals led the federal government, in 2000, to create the highly touted federal class-size-reduction program, which gave states funding to recruit, hire, and train new teachers. Under the reauthorized Elementary and Secondary School Act—popularly known as "No Child Left Behind" Act of 2001—that program was consolidated into a more general teacher-quality block-grant program funded at $2.85 billion for 2002.

Research, for the most part, tends to support the belief in the benefits of small classes. While not all studies on the subject have shown that students learn more in smaller settings—and while many are still ongoing—most studies have found some benefits.

Tennessee researchers found that poor and African-American students appeared to reap the greatest learning gains in smaller classes.

The biggest and most credible of them, a statewide study begun in Tennessee in the late 1970s, has even found that the learning gains students make in classes of 13 to 17 students persist long after the students move back into average-size classes. What's more, the Tennessee researchers found, poor and African-American students appeared to reap the greatest learning gains in smaller classes. After kindergarten, the gains black students made in smaller classes were typically twice as large as those for whites.

Likewise, a 2001 evaluation by researchers at the Education Policy Studies Laboratory and the University of Wisconsin-Milwaukee found that a 5-year-old program of class-size reduction in Wisconsin has resulted in higher achievement for children living in poverty.

But, as school improvement ideas go, reducing class sizes is costlier than many others and more complicated than it appears on first blush.

With many communities already facing shortages of qualified teachers, one concern is that the press for quantity will come at the expense of quality, forcing schools and districts to hire underqualified or unprepared teachers.

California learned that lesson firsthand when the state undertook its own class-size-reduction initiative beginning in 1996. In the first year of implementation, more than a fifth of the new teachers hired in that state had only emergency credentials. Hit hardest were schools serving poor and minority students. And, in the hunt for new space, administrators found themselves carving classrooms out of broom closets and erecting portable classrooms on playgrounds.

California's experience has some researchers wondering whether other improvement strategies, such as better professional development for teachers, might be more cost-effective. Indeed, as the economy tightened in 2001 and 2002, several California districts facing budget shorfalls were thinking about eliminating part or all of their class-size programs.

The California, Tennessee, and Wisconsin class-size-reduction efforts were all aimed at pupils in kindergarten through 3rd grade. Less is known about the effects of smaller classes on older students.

Researchers agree, however, that shrinking the number of students in a class does not automatically translate into better learning. To squeeze the most out of their new settings, teachers may need to alter their teaching practices, dropping lecture-style approaches and providing more frequent feedback and interaction. But studies so far show that many teachers teach smaller classes the same way they did larger ones.