This paper describes three paradigmatic "change facilitator styles": initiator, manager, and responder. These styles were identified through observations of principals' school improvement practices and the effects that those practices had on implementation at the classroom level. Initiators have clear, decisive long-range policies and goals that transcend but include implementation of the current innovation. Managers combine responsive behavior with initiating actions; the variations in their behavior are linked to their rapport with teachers and central office staff, and to their understanding and acceptance of a change effort. Responders focus on traditional administrative tasks, allowing teachers to take the lead in initiating change; they tend to make decisions in response to immediate circumstances, rather than in accordance with long-range goals. The Principal-Teacher Interaction Study, in which nine elementary school principals from three school districts and their staffs involved in the implementation of curriculum innovations were studied, is described. The overall conclusion of the systematic study is cited: principals did indeed carry out interventions in ways consistent with each of the three change facilitator styles previously identified. Implications of these three styles for training of principals, the planning of implementation efforts, and the monitoring of school improvement and school effectiveness efforts are discussed. (TE)