Dan Willingham offers an interesting conceptual analysis on how to improve teacher evaluation here. Essentially, he says that the diagnostic can go both ways, either by over- or under-identifying which teachers aren’t performing up to snuff. Finding the appropriate balance is tricky, and the unions need to advance this conversation, he writes, but that’s hard for them to do because of their role as teachers’ protectors.
The inimitable Andy Rotherham’s take on it is here. Unions, he writes, “don’t want to use data to evaluate teachers and they don’t want to use managerial discretion. I guess that leaves the Magic 8-Ball?”
In seriousness, I myself mused about this subjective/objective dichotomy not too long ago here, and these issues of accuracy are worth exploring. First, for the grand majority of our teachers, evaluations have to serve as a road map toward improvement. Too often they don’t. And secondly, no one wants a system to misidentify or penalize effective teachers. But neither should kids have to bear the brunt of ineffective teachers.