Introduction: What Do We Know about School Size and Class Size?

The world of education is never hurting for new reforms. For decades, one new proposal after another—in areas ranging from pedagogy to governance to school finance—has been championed by enthusiastic backers. The most successful of these have been embraced by researchers, policymakers, or influential philanthropists and become part of the fabric of schooling. Unfortunately, the track record of most reforms has been disappointing. Many highly touted proposals—site-based governance, whole language, alternative schools, and mastery learning, just to name a few—had their brief moment in the sun, then receded into the background with little evidence that they had improved education.

Today, two of the more prominent reforms on the agenda address the question of size. For more than a decade, an influential camp of education experts has argued that smaller classes are a promising way to boost student achievement. Ambitious, costly class-size reduction policies have been adopted in trendsetting states like California and Florida. Influential organizations, including the National Education Association, have made class-size reduction a favored policy proposal.

More recently, the criticism has arisen that contemporary high schools are too big and too impersonal to educate today's students effectively. One reform strategy, supported aggressively in the early 2000s by the influential Bill and Melinda Gates Foundation, has been to break up these large institutions and replace them with smaller, more intimate schools. The "small schools" strategy—which has been an organizing principle of high school improvement efforts in closely watched urban districts like New York City and San Diego and in heralded charter schools in cities like Providence and Boston—has attracted much notice and some criticism. While the Gates Foundation has gradually backed away from the small schools focus in the past year or two, it remains a popular tack for high school reformers across the land.

What are we to make of these reforms? What do we know about their benefits and costs or about how they actually affect the lives of students, teachers, and parents?

Both small classes and small schools would seem to be an easy sell. Smaller classes offer teachers more time to address the individual needs of each student. Smaller schools foster a more personal, tightly knit environment in which adults know individual students well. Most people believe that smaller, intimate educational settings provide structure, safety, and discipline that larger, bureaucratized settings cannot provide.

Of course, smallness is not cost free, whether it means reducing the size of schools or the size of classes. Both forms of downsizing incur direct costs—it costs money to shrink classes by hiring more teachers or to shrink schools by adding new campuses or subdividing existing schools—and indirect costs can develop downstream from the additional organizational changes precipitated by going small. However, researchers, politicians, philanthropists, and school reformers often tout the potential benefits of small schools and classes while giving scant attention to either the cost or difficulty of downsizing. A political environment in which costs are downplayed or ignored presents a real challenge for policymakers.

Class-size reductions are wildly popular. Doug Harris notes in this volume that 88 percent of parents reportedly support class-size reduction. Teachers also strongly endorse it; both major national teacher unions have made class-size reduction central to their school reform agendas. The American Educational Research Association (AERA), the professional association of the nation's educational researchers, issued a policy brief in 2003 that advised public officials and educators that "in the stockpile of educational policy initiatives that are worth finding resources for, small classes rank near the top of the list." The AERA brief declared, "There is no doubt that small classes can deliver lasting benefits, especially for minority and low-income students," but also admitted that "unintended consequences are possible" and that reducing class size "may not always be the best use of scarce resources."¹

Buffeted by such research and advice, policymakers face difficult decisions. In this volume, we offer guidance on how to think through the popular calls for smaller classes and smaller schools. In the spring of...