‘Well I’ll be VAMned!’ Why using student test scores to evaluate teachers is a sham

If by now you don’t know what VAM is, you should. It’s shorthand for value-added modeling (or value-added measurement), developed by economists as a way to determine how much “value” a teacher brings to a student’s standardized test score. These formulas are said by supporters to be able to factor out things such as a student’s intelligence, whether the student is hungry, sick or is subject to violence at home, or any other factor that could affect performance on a test beyond the teacher’s input. 


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