We’ve been following the response to the report of a massive $2.5 million, 20 year study of teacher value added measures that appeared in Saturday’s NY Times.
The United Federation of Teachers leader Leo Casey asks why was the study released now, without the usual peer review?
Good question.
The choice of this particular moment, with the NYC DoE walking out of negotiations with the UFT over the teacher evaluation system for the 33 PLA schools, State Education Commissioner King’s disallowance of the teacher evaluation plans of all ten major urban school districts and Governor Cuomo’s announcement in the State of the State address that he would take up the matter of teacher evaluation, is telling. Combined with the assertion by the CFR authors that their study supported the mass firings of teachers identified as low-performing by value-added measures, this moment points to the political nature of the CFR authors’ abandonment of scholarly ‘peer reviewed’ norms for the publication of research. Their decision serves well their partisan political purpose. It is just the quality of debate and decision-making around important public policy choices that suffers.
Fred Klonsky 
Here’s a possible explanation for the findings: Students are not assigned randomly to teachers. For good reasons or bad, some teachers tend to get students who learn fast and score higher, while other teachers tend to get students who score low–even in the same school with the same demographics. High-scoring students also, on average, probably have lower teenage-pregnancy rates and higher college matriculation and adult earnings. But that doesn’t mean the teacher made it happen.
The same explanation may be behind the very strange research finding that you can “predict” a student’s fourth grade test scores if you know who that child’s fifth grade teacher was — even though the child may never have met that teacher. The fifth grade teacher can’t really influence the student’s fourth grade scores, but the fourth grade scores influence who the fifth grade teacher will be.
That study is described in a paper by 10 leading education researchers who present lots more research evidence against relying on “value-added” scores for judging teachers. The paper is linked from http://www.epi.org/publication/bp278/