The intent of large-scale assessment systems is to promote student achievement toward specific standards by holding schools accountable for the performance of all students. However, it is difficult to know whether large-scale assessment systems are having this intended effect as they are currently implemented. In this article, the authors examine the research on intended and unintended consequences of large-scale assessment and accountability systems, highlight critical issues in using large-scale assessment programs to measure student learning and to inform intervention, and provide guidelines for promoting the intervention validity of large-scale assessments.