CARSON CITY — As Nevada policymakers work to remove ineffective teachers from classrooms, a new report provides evidence to support the use of test scores in measuring how much individual teachers contribute to pupil achievement.
Using quantitative measures to evaluate teachers, known as value-added modeling, or VAM, remains controversial, said Marcus Winters, a senior fellow with the Manhattan Institute’s Center for State and Local Leadership.
But in his report released Wednesday titled “Transforming Tenure: Using Value-Added Modeling to Identify Ineffective Teachers,” Winters said his analysis using data from Florida public schools shows that a VAM score in a teacher’s third year in the classroom is a good predictor of that teacher’s success in the fifth year of teaching after receiving tenure.
“VAM is not a perfect measure of teacher quality because, like any statistical test, it is subject to random measurement errors,” Winters said in his report. “So it should not be regarded as the ‘magic bullet’ solution to the problem of evaluating teacher performance.
“However, the method is reliable enough to be part of a sensible policy of tenure reform — one that replaces ‘automatic’ tenure with rigorous evaluation of new candidates and periodic reexamination of those who have already received tenure,” he said.