This project targets 42 schools in two school districts near the University of Alabama, Huntsville. Each of the 42 schools will have a leader/master teacher in grades K-1, grades 2-3, and grades 4-5 for a total of 126 leader/master teachers. Participants will be selected on the basis of potential for leadership, dedication to science, willingness to help other teachers, and prior experience in teaching hands-on science. The 2-year training plan includes 45 days of instruction per teacher from university science and education faculty. The cadre of leader/master teachers will train all K-5 teachers in activity-inquiry teaching and join with the principal and school resource scientist in forming leadership teams to lead all elementary schools in implementing a curriculum using nationally developed and tested hands-on modules. The two school districts are creating a materials management program to provide kits of STC or INSIGHTS materials for every classroom on a continuing basis. This leadership proposal is appropriate for teacher enhancement because it is designed to enhance the science knowledge and teaching, and develop leadership skills and efforts of lead teachers of grades k-5, and because it is a systemic plan designed to improve science education in all elementary classrooms in the participating districts. Non-NSF cost-sharing is approximately 47% of the amount requested from NSF.