Value-added estimates of teacher or school quality are increasingly used for both high- and low-stakes accountability purposes, making understanding of their limitations critical. A review of the recent value-added literature suggests three concerns with the state of the research. First, the issues receiving the most research attention have not always been the concerns of greatest importance to theorists or critics. Second, there has been insufficient research on the interactions among various issues or assumption violations. Third, some of the big issues in value-added modeling have been challenging to address and may require educators to step back and answer some underlying philosophical questions about the nature of teacher and school quality.