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8/26/10

"Selecting On The Dependent Variable"

Many are skeptical of the current push to improve our education system by means of test-based “accountability” - hiring, firing, and paying teachers and administrators, as well as closing and retaining schools, based largely on test scores. They say it won’t work. I share their skepticism, because I think it will.

There is a simple logic to this approach: when you control the supply of teachers, leaders, and schools based on their ability to increase test scores, then this attribute will become increasingly common among these individuals and institutions. It is called “selecting on the dependent variable,” and it is, given the talent of the people overseeing this process and the money behind it, a decent bet to work in the long run.

Now, we all know the arguments about the limitations of test scores. We all know they’re largely true. Some people take them too far, others are too casual in their disregard. The question is not whether test scores provide a comprehensive measure of learning or subject mastery (of course they don’t). The better question is the extent to which teachers (and schools) who increase test scores a great deal are imparting and/or reinforcing the skills and traits that students will need after their K-12 education, relative to teachers who produce smaller gains. And this question remains largely unanswered...
All of it at Shankerblog.