Assessing student learning often promotes anxiety among students--and among teachers--not only because they worry about the results but because the items tested do not seem to reflect what students have learned. When assessment is student centered, however, it can promote learning and even motivation. Student-centered assessment shares many qualities with any good assessment. It articulates developmentally appropriate learning targets, and it provides feedback to students, teachers, districts, and states about how to deepen learning. It is also valid, reliable, practicable, and efficient. A balanced system of formative, interim, and summative assessments can support student-centered assessment and learning. Yet even an exquisitely balanced assessment system would present challenges. For one thing, the sheer quantity of assessment data threatens to be overwhelming. Even as new assessment processes are created, educators must work to ensure they are useful to and used by the appropriate audiences--students, teachers, schools, districts, and policymakers alike. It is also critical to continually assess the assessments to make sure that advances in design--and their implementation--are as student centered as possible.