We now know that William Sanders, the creator of Value-Added Measurement, which measures teacher quality with the methods of an agricultural statistician, is revered in the think tank world of D.C.
But Peter Greene, who teaches in a Pennsylvania high school, doesn’t think much of VAM.
He recounts how Sanders was inspired to think about measuring teachers based on his studies of radioactivity in cows that were downwind from a nuclear explosion (really!).
To which Sanders writes:
Oh, let’s tell the truth. VAM systems have also been limited by the fact that they’re junk, taking bad data from test scores, massaging them through an opaque and improbable mathematical model to arrive at conclusions that are volatile and inconsistent and which a myriad educators have looked at and responded, “Well, this can’t possible be right.”
You’ll never find me arguing against any accountability; taxpayers (and I am one) have the right to know how their money is spent. But Sander’s work ultimately wasted a lot of time and money and produced a system about as effective as checking toad warts under a full moon– worse, because it looked all number and sciencey and so lots of suckers believed in it. Carey can be the apologist crafting it all into a charming and earnest tale, but the bottom line is that VAM has done plenty of damage, and we’d all be better off if Sanders had stuck to his radioactive cows.
from sarah http://ift.tt/2r9ScBQ