Six school-based improvement programs distributed throughout the United States were studied in order to determine how effective these plans have been and what factors help or hinder them. The programs studied shared three central features: 1) focus on the school as a whole; 2) involvement of teachers in designing improvements; and 3) incorporation of elements of rational planning. It was found that while school staffs are able to establish a continuous planning and review process, these processes do not necessarily lead to improved instruction. Two important factors for achieving instructional improvement were found to be the instructional content and support for change. The conditions they found necessary for achieving improvement were that preconditions for change existed, that there was instructional leadership within the school, and that conditions outside the school (i.e. Federal or State government) were favorable. The general conclusions were that: 1) the concept of treating the school as an organizational entity and developing a process for ongoing planning and review with staff involvement is sound; 2) the creation of school based planning and change is difficult; 3) the fact that planning groups can be formed, even though they may not immediately cause instructional improvement, is hopeful; 4) there is little evidence that the most needy students will be overlooked in school-based improvement plans, although more serious risks lie at the district level and disadvantaged schools require more resources; 5) the kinds of knowledge, skills and actions essential to instructional leadership can be used as criteria for identifying and training local staff as change agents and to develop and expand preservice training programs. (CG)