I will protect your pensions. Nothing about your pension is going to change when I am governor. - Chris Christie, "An Open Letter to the Teachers of NJ" October, 2009

Thursday, February 17, 2011

VAM/Media Fail

Value-Added Modeling - which uses standardized test scores to rate teachers - is an abject failure. But it's not nearly as big of a failure as the reporting at the LA Times:

 What is at stake here is not a battle over semantics or arcane statistical details. The Times contends that the teacher effectiveness ratings it published online were built on sound research, offering a fair and reliable assessment of the relative quality of individual teachers in the Los Angeles Unified School District. Parents are encouraged to rely on its searchable database in order to make choices about who will teach their children. 
The NEPC report explains that the model used to construct the Times’ teacher database is not adequate to that task. Using a stronger, alternative model, 53.6% of the teachers in the database would fall into a different effectiveness category for reading than the one assigned by the Times. While the NEPC researchers explain why they think a stronger model is preferable, that‟s not really the point. Instead, the point is this: when two reasonable models reach such different results, the Times’ decision to publish ratings based on their preferred model is reckless. [emphasis mine]
Read the whole thing; the mendacity of the LAT is a sight to behold. It's especially galling to see them question NEPC's motivations when their motivation to rake in dollars puts their own objectivity at grave risk. As the NEPC reports says:
Comment: It is peculiar that the Times fails to see that commissioning a study and then vehemently defending it when it is found to be flawed represents a conflict of interest of a far greater magnitude than that suggested by the line of attack directed at us. Is it appropriate for a newspaper to create news, defend that work in a “news” story that misrepresents a critique, subsequently attack those offering the critique, and then represent its own account as the work of unbiased reporters? 
I'm going to say, "No."

This method, by the way, is how teachers will gain or lose tenure and merit pay. Swell.

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