Educators can no longer count on public approval, trust, or support to help them guide students' learning. External forces are now calling the shots of daily practice through state and federal accountability testing, unfunded legislative mandates, print and television media exposes, as well as special interest groups lobbying for their students above all others. The old adage "All children can learn" is followed with the question "But can they?" In too many schools, the principal is expected to answer this and all other questions about learning, teaching, and student achievement. How can principals help others see the vision, educate students in a learning community, collaborate with groups and individuals who have myriad agendas, and still connect with students and improve their learning? Principals need curricular and instructional strategies, awareness of trends and pitfalls in the field, leadership processes that ensure feedback loops, and shared ownership and commitment to learning. In short, they need to plan, do, study, and act. In this article, the authors emphasize that using data effectively is a principal's best tool for initiating and sustaining change. They present key questions that help in assessing the school's strengths and weaknesses, identifying what needs to be improved, and planning a way to succeed.