I don't agree that we can't make these correlations between student performances on tests and teacher effectiveness. But I do wonder what would happen to the children. If I am going to make another $5000 a year if my students all move X distance in a year, how much more inclined am I going to be to add lots and lots of homework in my content area to their workload? We might end up like Japan with a very high teenage suicide rate from all the pressure to perform at a young age. Where is the middle ground? Some schools reward grade levels, if all the students in ninth grade do x, everyone who taught them gets y. Makes more sense, but doesn't address the teacher competency test.