It sounds so simple. If tests measure what a student learned, why can't they also be used to measure what a teacher taught? Wouldn't this data make it easy to distinguish good teachers from bad? And can't this information be used in teacher retention, tenure, salary, and other decisions? The use of student performance data to judge the quality of teachers looks like a magic bullet to some education policy makers. Convinced that poor teachers are the primary cause of low student achievement, they argue that "value-added models" (VAMs) can make it easier for administrators to identify and fire under performers. But will it? In January, the Educational Testing Service (ETS) hosted a symposium to answer some of these questions. The event showcased noted researchers and statisticians who have studied VAM extensively. The purpose of the symposium was to interject legitimate and current research into a debate, which to this point, has featured more rhetoric than reason. Experts addressed what effective teacher evaluation systems should look like and explained VAM's weaknesses and areas of promise. Free from political agenda, the researchers provided an assessment of the state of teacher assessment. This article discusses the major themes of the symposium.