A Pilot Off Course
There is an important point to be made about New Jersey's "pilot" program for teacher evaluation:
Against the recommendations of many researchers, and in contradiction to the evidence, the Department of Education is insisting on basing 45% of a teacher's evaluation on test scores. Let's leave aside the completelyunworkable timeline and lack of oversight of the tests themselves and look at something that is, admittedly, a little technical but critical to understand.
There are two ways to evaluate a teacher's impact on a student's test scores. First, we can try to adjust for factors that are beyond a teacher's control: all of the things that happen outside of the classroom in a student's life, and the characteristics of the student himself. Value-Added Modeling (VAM) is an attempt to do just this. Essentially, we make a prediction about how well a student will do on a test by looking at a student's previous performance. We then compare that prediction to the actual score: if a student does better, or worse, we
Against the recommendations of many researchers, and in contradiction to the evidence, the Department of Education is insisting on basing 45% of a teacher's evaluation on test scores. Let's leave aside the completelyunworkable timeline and lack of oversight of the tests themselves and look at something that is, admittedly, a little technical but critical to understand.
There are two ways to evaluate a teacher's impact on a student's test scores. First, we can try to adjust for factors that are beyond a teacher's control: all of the things that happen outside of the classroom in a student's life, and the characteristics of the student himself. Value-Added Modeling (VAM) is an attempt to do just this. Essentially, we make a prediction about how well a student will do on a test by looking at a student's previous performance. We then compare that prediction to the actual score: if a student does better, or worse, we
