Sunday, August 29, 2010
Just when you thought it was safe to go back in the water...so goes the old JAWS promo. I thought the water for teachers would be a little safer when the Bush administration packed it in. First came Obama's "Race to the Top," (why must it always be a competition with winners and losers?) and then this bizarre notion of "value added" teachers from an article in the L. A. Times. Now you know by the sound of that phrase the business model applied to public education is alive and well. A small amount of research leads you to this wonderful paragraph from the Rand Corporation's study linking achievement tests to teacher "performance." (Hey, we're not trainin' seals heah!")
What Is a Teacher Effect?
Applications of VAM often model growth or gain scores as a means
of measuring the effects of incremental inputs on incremental out-
come—as the definition of value-added suggests (Hanushek, 1979).2
Appropriate interpretation of VAM results requires that the causal
effect be explicitly defined. Typically, there are multiple ways to de-
fine a causal effect, and some estimators can provide unbiased or con-
sistent estimates of some causal effects but not of others. For example,
Angrist, Imbens, and Rubin (1996) demonstrate that, under general
assumptions, instrumental variable estimators provide estimates of the
average causal effects of “treatment” on those who will take the
treatment when it is offered. However, they do not necessarily esti-
mate the causal effect of treatment on the entire population or on all
people who were offered treatment. Alternative assumptions are re-
quired to make inferences about those causal effects.
I often wonder about the amount of money used to produce and promote bullshit like that. I see children's faces, their hopes and fears, the daily substance or lack thereof in their lives. Who's zoomin' whom folks.
Then just when you thought...I heard last week about something promoted by the Gallup (as in polls) corporation purported to be a predictor of successful teaching. Apparently there is this "test" that is popular in many districts that has serious impact in determining who is hired and who is not. I've seen some of the questions and scenarios that this test uses. Sort of a multiple choice what would yo do type of thing. I don't know what is more chilling: a.) that prospective teachers are subjected to these things, b.) that admisistrators actually trust, validate, and believe this is time and money well spent or c.) all of the above.