The authors reviewed research on effective schools, literature on the implementation of educational innovation, and current theories of school organization. A synthesis of findings from this research indicates that differences among schools do have an effect on student achievement. Specifically, it is the school's culture that is responsible for that effect. Thirteen variables are identified as contributing to the development of a school culture conducive to academic achievement. Drawing on recent literature, the authors suggest federal and state policies that would be likely to facilitate the development of effective schools. Key recommendations include policies that promote building-specific, whole-school improvement efforts and that rely on outcomes as the preferable means of monitoring and evaluating school improvement efforts. (Author)