This document summarizes and compares two approaches to school improvement: the external research and development (R&D) approach and the school-based, faculty-centered approach. It outlines the key characteristics of each, including that the R&D approach involves experts designing programs that are field tested, while the school-based approach involves shared decision making at the school level. Both approaches can be effective if they focus on student benefits, use an inquiry process, involve staff and the community, and provide support for implementation. Common mistakes occur when advocates believe a single strategy will surely work without ongoing modification based on evaluation data.