Please Refrain from “Think[ing] of VAMs Like an Oak Tree”
It happened again. In the Tampa Bay Times a journalist encouraged his readers to, as per the title of his article, “Think of VAMs Like an Oak Tree” as folks in Florida are now beginning to interpret and consume Florida teachers’ “value-added” data. It even seems that folks there are “pass[ing] around the University of Wisconsin’s ‘[O]ak [T]ree [A]nalogy,” to help others understand, unfortunately, what is a very over-simplistic and overoptimistic version of the very complex realities surrounding VAMs.
He, and others, obviously missed the memo.
So, I am redirecting current and future readers to Stanford Professor Edward Haertel’s deconstruction of the “Oak Tree Analogy,” so that we all might better spread the word about this faulty analogy.
I have also re-pasted Professor Haertel’s critique below:
“The Value-Added Research Center’s ‘Oak Tree’ analogy is helpful in conveying the theory [emphasis added] behind value-added models. To compare the two gardeners, we adjust away various influences that are out of the gardeners’ control, and then, as with value added, we just assume that whatever is left over must have been due to the gardener. But, we can draw some important lessons from this analogy in addition to those
