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The War On Error


How do we correct for teachers that work with consistently high or low students? A teacher of gifted students may seem to be adding a lot of value the their students while a Special Ed teacher may not add as much, but I think smaller gains in s SPED class might be more remarkable than barely above average gains in a gifted classroom.

The problem Brenden Murphy cites may emerge in precisely the opposite fashion as well -- for example, G & T kids score so high to begin with that they hit the ceiling immediately, making it look like the teacher is adding little when he/she may be adding a lot...

Brendan and Denis - thanks for your comments. Most VAM models do employ techniques to correct for student "ability" (e.g., by controlling for their prior performance), but you're certainly correct in pointing out that there are dozens of unmeasurable factors that might bias the results of individual teachers (including, as Brendan notes, non-random assignment of students to teachers). In my view, however, this only makes it more important for states and districts that are already moving ahead to address the error that they CAN address, right?


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