Teacher Misclassification in High Stakes Personnel Decisions

Posted by on April 29, 2013

Flawed measures, but the best we’ve got

What Do We Know About the Tradeoffs Associated with Teacher Misclassification in High Stakes Personnel Decisions?

A new paper from the Carnegie Knowledge Networks weighs the trade-offs of using teacher value-added scores in personnel and compensation decisions. The authors conclude that grouping teachers in performance categories inevitably leads to mistakes, regardless of when in her career a teacher is evaluated, whether for high or low stakes, or how the evaluation is conducted. True performance is not fully observable and measures are always imperfect. Measures based on student test scores have a high number of classification errors, but fewer than those based on licensure status or years of experience. In effectiveness ratings, “false positives” classify a teacher as belonging in a group where he does not belong (e.g., effective teachers), and “false negatives” place him into a group where he does (ineffective). Since current evaluation systems rarely classify teachers as ineffective or needing improvement, the “false negative” rate for these classifications is likely high. The authors conclude that better measurement can reduce misclassification, and better balancing of errors, and careful consideration of the consequences of these errors, can reduce the harm of misclassification. To achieve more accurate classification, the authors recommend continued research on measurement, on tradeoffs between false positives and false negatives, and on structuring the consequences associated with classification.

http://www.carnegieknowledgenetwork.org/briefs/value-added/teacher-misclassifications/