The silly argument on teacher evaluations presented as mathematical equations. #netDE #eduDE

From Bruce Baker: http://schoolfinance101.wordpress.com/2010/09/30/on-false-dichotomies-and-warped-logic/

 

“Reformers” continue to press the argument that current teacher evaluations are so bad, so unreliable, that anything is better than this “status quo.”

Expressed mathematically:

Anything > Status Quo

Bear with me while I use the “greater than” symbol to imply “really freakin’ better than… if not totally awesome… wicked awesome in fact,” but since it’s relative, it would have be “wicked awesomer.”

Because value-added modeling exists and purports to measure teacher effectiveness, it therefore counts as “something,” which is a subclass of “anything” and therefore it is better than the “status quo.” That is:

Value-added modeling = “something”

Something ⊆ Anything (something is a subset of anything)

Something > Status Quo

Value-added modeling > Current Teacher Evaluation

Again, where “>”  means “awesomer” even though we know that current teacher evaluation is anything but awesome.

It’s just that simple!

After all, you can’t even measure the error rate in current principal and supervisor evaluations of teachers can you? And if you can’t measure the error rate it must be higher than any error rate you can measure? More really basic reformy logic! That is, the unobserved error rate in one system is necessarily greater than the observed error rate of another – even if we have no way to quantify it – in fact, because we have no way to quantify it?

Unobserved error rate of ‘status quo’ > measured error rate of VAM

Let’s be really blunt here. Both are patently stupid arguments.

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