School districts across the United States increasingly use value-added models (VAMs) to evaluate teachers. In practice, VAMs typically rely on lagged test scores from the previous academic year, which necessarily conflate summer with school-year learning and potentially bias estimates of teacher effectiveness. We investigate the practical…

Educators struggle with "value-added" teacher evaluation models based on high-stakes student assessments. Despite validity and reliability threats, these models evaluate university-based teacher preparation programs (TPPs), and play a role in state and professional accreditation. This study reports a more rational value-added evaluation…