Three main models of SBM have emerged (Bimber, 1993; Wohlstetter and Odden, 1992). The first model places principals in control, with this individual serving as a chief executive with broad-reaching powers over budget, staffing, and program design. There may be some kind of school-site council, but it tends to serve in an advisory rather than decision making capacity. The second model focuses on administrative decentralization, delegating decision making to teachers and giving them broad discretion over the professional judgments needed each day as they encounter students in classroom learning situations. School-site councils under this model tend to give the greatest representation to teachers and other school-site educators. The third model is characterized by a shift of power from educators to community-based control. Most visibly exemplified in the 1988 Chicago school reforms, this approach shifts power from the school board and professional educators to parent and community representatives by giving them majority representation on school-site councils with significant control over budgets, personnel, management, and program design.
Evaluation of SBM has been hampered by the multiplicity of objectives and practices that have been pursued, by the fact that real devolution of decision making to the school level has been far less than the rhetoric around SBM would imply, and by the failure of most of the research on SBM (as revealed in a literature review by Summers and Johnson, 1996) even to address the question of effects on student achievement. Assessments based largely on SBM as it was implemented in the 1970s and 1980s suggested that it seldom had the positive benefits predicted for it, either in terms of improving student achievement or changing the behavior of schools and school participants (Malen et al., 1990; Murphy and Beck, 1995; Newmann and Wehlage, 1995; Summers and Johnson, 1996; Wohlstetter and Odden, 1992). More recent research (Odden and Busch, 1998; see Chapter 6) suggests that older strategies of SBM lacked the necessary organizational conditions for it to lead to improved student achievement.
While much restructuring has focused on the school level, there have also been efforts to reform district operations, to reorient them toward improvements in teaching and learning while retaining a significant measure of central control. One prominent example is Community School District #2 in New York City, which has based a comprehensive and sustained district-wide reform agenda on a strategy of instructional improvement through professional development. While more and more budget and administrative responsibility has been lodged at the school level, largely in the hands of principals, central control has remained strong in areas key to the success of the strategy, such as personnel decisions, the hiring of professional development consultants with expertise consistent with the strategy, decisions about which instructional areas will receive priority attention, and policies and practices that keep school-site decisions focused on district-wide priorities (Elmore, 1997a).
Changes in school and district practice, based to a greater or lesser extent on the research base developed using the lens of effective practice, have clearly had an impact on American schools. What is much less clear at this point is whether