This three-year Master's degree program is designed to train two groups of 40 well-prepared high school mathematics teachers to provide leadership in modernizing mathematics teaching in the greater Los Angeles area. The program includes the study of mathematical content, pedagogical issues, and leadership skill development. It focuses especially on the importance of visualization in mathematics--emphasizing applications of computers and graphing calculators. The program format consists of a 2-3 week summer institute, a 3-semester hour course in the fall, a 2-day winter workshop, and a course meeting for three long weekends in the spring. This basic format is repeated in each of the three years. Year 1 focuses on mathematical content, alternative teaching styles, and familiarizing participants with technology and its applications in the classroom. During Year 2, participants assemble and adapt suitable curricular materials, and implement them in their classrooms--while, at the same time, they observe, document, and reflect on the changes in themselves and their students. Year 3 focuses on developing, practicing, and exercising leadership skills: participants are expected to present at local conferences, give in-service workshops, and--in cooperation with project staff--plan and put on local teacher conferences. A master's thesis is required for the degree. Plans call for supporting the participants in their implementation, dissemination, and reform efforts by means of electronic networking, periodic meetings, and a newsletter.