You might have heard by now that New York City plans to publicly release teacher evaluation scores with names attached. I’ve dealt with some of the statistical issues surrounding using value-added testing to grade teachers (as opposed to assessing large-scale school or curriculum performance), the most obvious flaws being that the year-to-year variability in scores and the huge margin of error. While publishing the margin of error might help–if nothing else, it would reveal how ridiculous many of these scores are–most people will ignore them (assuming they’re printed by newspapers in the first place).

Few people seem to realize that the publication of the scores will, over time, make the scores less reliable. Why? Because parents will start to choose teachers (and, if possible, schools) based on the scores. More motivated parents, along with those with the economic means to spend time on choosing schools (i.e., not poor), will place their students with higher-scoring teachers, introducing bias into the estimates (teacher assignment will be non-random).

What is encouraging is that even education ‘reformers’ hate this plan, including Teach for America’s Wendy Kopp and Bill Gates. While I think Gates is fundamentally wrong on the problems facing U.S. education, he is absolutely right in opposing the release (boldface mine):

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.

Putting sophisticated personnel systems in place is going to take a serious commitment. Those who believe we can do it on the cheap — by doing things like making individual teachers’ performance reports public — are underestimating the level of resources needed to spur real improvement.

At Microsoft, we created a rigorous personnel system, but we would never have thought about using employee evaluations to embarrass people, much less publish them in a newspaper. A good personnel system encourages employees and managers to work together to set clear, achievable goals. Annual reviews are a diagnostic tool to help employees reflect on their performance, get honest feedback and create a plan for improvement. Many other businesses and public sector employers embrace this approach, and that’s where the focus should be in education: school leaders and teachers working together to get better.

I agree with Gates, but that’s never how ‘reformers’ have perceived this problem.

They have always viewed the fundamental problem in U.S. education as the inability to fire teachers at will, even though the charter school experiment demolishes that argument. Given that many advocates of this approach come from corporate cultures that have disdain for their workers, this shouldn’t come as a surprise. They have very little respect for teachers or for the idea that teachers should have significant input in how they teach (they don’t let their workers do this, why should teachers?).

What is really frustrating is how many progressives have bought into this notion, while completely ignoring the massive effects of poverty. Of course, when it comes to how they would like their own children to be educated, these progressive useful idiots (along with their corporate backers) choose schools that typically renounce what they advocate.

This is a dreadful mistake. I only hope this leads to a backlash against ‘reformers.’