Value-Added Teacher Evaluation

Value-added teacher evaluation uses longitudinal student test scores to estimate how much individual teachers contribute to their students' achievement growth, net of what students brought into the classroom. Statistically it applies value-added and mixed-model machinery — controlling for prior achievement and student characteristics, then treating each teacher's residual contribution as an effect to be estimated. Pioneered in Tennessee's TVAAS and scrutinized in a large methodological and policy literature, it became central, and controversial, in teacher accountability.