In the midst of keen controversies on the impact of high-stakes testing and test-driven external accountability policy, the more balanced and careful selection, interpretation, and use of scientific research evidence are crucial. This article offers a critical synthesis of cross-state causal-comparative and correlational studies that explored the…

The insightful discussions by Raudenbush, Rubin, Stuart and Zanutto (RSZ) and Reckase identify important challenges for interpreting the output of VAM and for its use with test-based accountability. As these authors note, VAM are statistical models for the correlations among scores from students who share common teachers or schools during the…