Who should make the most important decisions about how a school is run? Traditionally, it has been the principal, who gets lots of advice from district administrators and school boards. In the last decade, however, reformers have called for a much bigger role for teachers in making decisions at the school level, especially in matters of curriculum, instruction, and assessment—the core issues that are most directly related to students' learning. The Carnegie Forum on Education and the Economy and the Holmes Group, among others, in their reports on the future of teaching as a profession, advocated decentralized control of public schools and the empowerment of teachers.

Efforts to promote site-based management of public schools often take for granted the superiority of shared decision-making, where teachers and administrators jointly take responsibility for making school policy. But recent research suggests that some common assumptions underlying the arguments for shared decision-making are overoptimistic. These studies indicate that simply moving decision-making power from one set of actors to another doesn't necessarily change the quality of those decisions. And they reinforce the conclusion of other researchers that, when it comes to making significant changes in practice, it is the principal's leadership and vision that most often provide the essential push.