This article summarizes some of the main issues, concerns, and debates that have ensued over the years in the field of L2 assessment and shows how past concerns have shaped contemporary L2 assessment research and practice. The article first describes what L2 assessment is and what it entails, arguing that notions of L2 assessment have been broadened over the years to keep pace with contemporary interpretations of how information from assessments in large-scale or classroom contexts is used to make decisions. It then describes in some detail four approaches to construct definition, showing how these approaches have influenced what gets assessed. Finally, the paper discusses a range of other topics of current and future importance for L2 assessment theory, research, and practice.