This proposal describes the Philadelphia Elementary Science Teacher Leader Program which will establish 28 teacher- principal teams of 84 public and parochial educators in grades 1-3 as leaders in the citywide implementation of a new activity-based program for elementary science study. Two teachers and a principal will be selected as a team from each of twenty-eight schools. The three year project will increase the teachers' knowledge of elementary science content, promote peer leadership and support, and establish the teachers as experienced curriculum writers through a three-year agenda of Summer Science Institutes and six annual professional development colloquia. These teachers and principals will develop permanent roles as leaders of required in-service workshops on the effective use of elementary science kits for the city's public and parochial school teachers. The three-week summer workshops will cover the content areas of physical, earth and life sciences. The teachers will be provided with practical experiences in running in-service workshops for their peers. The workshops will also provide a framework for collegial evaluation in the development of interdisciplinary activities based on hands-on science lessons. In addition, all participants will attend a one- week Institute during July of 1993 to further evaluate the impact of the Elementary Science Teacher Leader project and plan for the permanence and expansion of the Teacher Leadership roles. The School Department of Philadelphia and the Office of Catholic Education are supporting the released time, the purchase of the elementary science kits in sufficient number to implement the program in all their elementary schools, the salaries of school district liaisons, school-based follow-up workshops and other materials necessary for the project. The actual dollar cost-share from the schools and the Franklin Institute to implement this science kit, activity-based, leader teacher/principal approach to improve elementary science education is equivalent to 170% of the NSF request.