(via adventuresinlearning)

There’s a little like logic-defying chestnut in the piece:

Teachers have reason to fear they may be misidentified — roughly one in four would be even after three years of data have been collected, according to a report last month commissioned by the Department of Education. Hanley Chiang, a Mathematica Policy Research researcher who co-authored the report, said, “How tolerable these error rates are, is really a policy judgment.”

Which, really?! The data misidentify teachers at a rate of 25%? That sounds like an unusable set of data, then.