William L. Sanders, the statistician and researcher who developed the controversial value-added system for evaluating teachers based on student growth, died March 16. He was 74.
The model determines how much value a teacher adds to a student’s learning, as measured by standardized-test scores.
Sanders developed the Tennessee Value-Added Assessment System, which rolled out in 2011-12 and has been the subject of several lawsuits brought by the state teachers’ union. Yet it has also been emulated in other states and districts. Critics of the value-added method say it doesn’t sufficiently control for such factors as student poverty.
Sanders, however, believed that teacher effectiveness was the largest predictor of student academic growth. He held that his teacher-evaluation system was fairer than any other system and that the goal was not to dismiss weak teachers, but rather improve their practice.
