Reports an evaluation of Edison Schools, the nation's largest for-profit manager of public schools. RAND analyzed Edison's school improvement strategies, the implementation of those strategies, and effects on student achievement. In 2000, Edison Schools, the nation's largest education management organization, asked RAND to analyze its achievement outcomes and design implementation. RAND evaluated Edison's strategies for promoting student achievement in its schools, how it implemented those strategies, how its management affected student achievement, and what factors explained differences in achievement trends among its schools.