For several years, there have been varying and often conflicting viewpoints and definitions of what formative assessment is--is it a product, is it a process, is it something that can be bought? One source of confusion about this issue has come from products and services sold by curriculum and assessment vendors, touted as "formative assessment." The need to be clear about what formative assessment is has never been more magnified. This Connecting Research to Practice brief is intended to enhance the knowledge and build the capacity of state, district, and school personnel to implement effective formative assessment practice. To accomplish this goal, the brief defines formative assessment, examines the research, and outlines the components needed to develop a high-quality, research-based formative assessment plan in a state, district, or school. (Contains 2 figures and 6 online resources.)