To understand more about policies and practices that can improve student motivation, the Center on Education Policy (CEP) reviewed research on motivation conducted by scholars in various disciplines, read studies of motivational programs, gathered news articles and blogs about motivational strategies, and used handbooks and other resources compiled by experts in the field. From this broad and complex array of information, we grouped what we learned into six general themes and developed this series of six papers, each focused on a different aspect of motivation. These papers highlight findings from research and lessons from programs around the country that we felt could be useful to policymakers, educators, and others interested in improving student motivation. These papers are not intended to be a comprehensive summary of research or lessons learned, but rather an opening of a conversation and an exploration of ideas that might spur further discussion of this critical topic. This first paper in the series examines two fundamental issues that are necessary to understand before delving deeper into the research literature: why student motivation matters and how the concept of "motivation" has been defined.