School Innovation in Science is a major Victorian Government initiative that developed and validated a model whereby schools can improve their science teaching and learning. The initiative was developed and rolled out to more than 400 schools over the period 2000-2004. A research team worked with 200+ primary and secondary schools over three years, supporting them in developing new initiatives in science, and monitoring the impact on school and classroom practice, and student outcomes. The research effort underpinning the development phase included the development and validation of a set of components describing effective teaching, the refinement of a school and teacher change strategy, the development of instruments to monitor teacher classroom practice and a variety of student outcomes, and the development of insights into the change process using questionnaires, observations, and interviews across four years. This paper describes the project and its major outcomes, and raises a number of issues concerning the nature of school and teacher change, pedagogy, school and community, and student learning, and the way these interact. A number of research issues are raised by the size and developmental nature of the project, the range of research methods, and the different audiences served by the research. The issue of sustainability of such system-wide change initiatives is discussed. (Contains 6 figures.)