I heard some push back last month when I praised Bill Gates for adopting a more holistic view of teacher evaluation, one focused less on student test scores and more on peer review and continuous improvement. But today he's signaling his evolution on these ideas in the loudest way possible, by publishing an op-ed in the New York Times that argues against releasing teachers' value-added scores to the public–a policy the Bloomberg administration and Arne Duncan support–and in favor of using value-added as just one measure of teacher effectiveness (emphasis added):
Many districts and states are trying to move toward better personnel systems for evaluation and improvement. Unfortunately, some education advocates in New York, Los Angeles and other cities are claiming that a good personnel system can be based on ranking teachers according to their “value-added rating” — a measurement of their impact on students’ test scores — and publicizing the names and rankings online and in the media. But shaming poorly performing teachers doesn’t fix the problem because it doesn’t give them specific feedback.
Value-added ratings are one important piece of a complete personnel system. But student test scores alone aren’t a sensitive enough measure to gauge effective teaching, nor are they diagnostic enough to identify areas of improvement. Teaching is multifaceted, complex work. A reliable evaluation system must incorporate other measures of effectiveness, like students’ feedback about their teachers and classroom observations by highly trained peer evaluators and principals.
Of course, the Gates Foundation is not abandoning value-added entirely; it continues to commit its own resources to developing value-added as an evaluation tool, in part by creating new, more stable student assessments, and in part by researching what combination of evaluation tools–both qualitative and quantitative–are least volatile and most predictive. But given Gates' history of statements on teaching, it's no longer credible to argue he hasn't evolved significantly in a direction most classroom teachers support: toward multiple measures of teacher quality.
For those interested in how to perform high quality classroom observations of teachers, I'll be moderating a panel on the subject on March 27 in New York, based on this paper by my colleagues at the New America Foundation, and featuring both researchers and educators. More info soon.