This report from the Achievement Gap Initiative (AGI) at Harvard University looks at 15 outstanding public high schools from Massachusetts, Illinois, Ohio, Maryland, Texas, and Washington, D.C. These high schools were featured at the fifth annual conference of the AGI in June 2009, where teams from each school made presentations and then faced questioning from experts about the methods by which they had achieved progress, such as high value-added test score gains on statewide assessment tests and narrowing test-score achievement gaps. The main lesson from the presentations was that student achievement rose when leadership teams focused on improving instruction. Leaders took public responsibility for raising achievement, and stakeholders drafted mission statements to help schools stay on track. Schools carefully organized learning experiences for teachers, and clearly defined criteria for high-quality teaching and student work in ways that engaged entire faculties. As leaders implemented plans, schools monitored student and teacher work to continuously refine approaches. Leadership teams demonstrated commitment through hard work and long hours, studying research-based literature to expand knowledge and competence, and found ways to remain respectful of peers, even when asking them to improve their performance. In these ways, leadership teams earned the respect of their colleagues and gained authority to push people outside their comfort zones.