Policymakers need information about the schools in their state. What programs are the most cost effective and work best for students? How can states attract and retain great teachers? What information do parents need to ensure that their kids are on track to graduate? For answers to questions like these, policymakers need high-quality data. Information is a critical tool to help inform policy decisions. Likewise, everyone involved in a child's education needs timely, accurate data to provide insights and drive improvements for students. Data has become a critical part of education policy conversations in every state, and this briefing book is meant to bring policymakers up to speed on the major topics they need to know about. Eight of the most pressing topics have been selected and described in this briefing book. Each topic area includes: (1) a basic overview of the topic; (2) why it matters; (3) the "state of play" on the latest progress states and others have made in that area; (4) recommendations to take action in your state; and (5) additional resources to help build your understanding of data topics and policies.