This report is one of a series produced by the National Center for Improving Science Education. The Center synthesizes and translates the findings, recommendations, and perspectives embodied in recent and forthcoming studies and reports in order to develop practical resources for policymakers and practitioners. Toward achieving the High School Panel's vision for a high school science education that provides all students with an opportunity for in-depth engagement with science, the Center presents a consistent and coherent blueprint addressing four aspects of science education: program; assessment; teaching; and teacher and organizational development. To meet the goals for program, assessment, teaching, and teachers, this report contains: (1) recommendations to guide program and policy development; (2) principles for course design, assessment reform, research-based teaching, teacher enhancement, and organizational restructuring; and (3) vignettes that illustrate how teachers and administrators can address practical and intellectual challenges they will face in implementing change. This document contains 75 references. (KR)