Thanks to David B. Cohen, I just learned about a very interesting article written by a former director of research from Education Testing Service.

Testing can help evaluate teachers, but it’s not the sole method: Too many factors affect how students perform, and lots of good teachers work hard for minor improvements is a long headline for a short, good article.

Here’s an excerpt:

Does this mean that testing makes no contribution to teaching? Absolutely not. Test scores tell teachers which students need help and where help is needed. And they also can tell school boards which schools need a bigger budget. Or a new principal.

But in evaluating a teacher, priority should be given to expert judgment. Principals and department heads worthy of their position know which teachers care about their students and know the strengths and needs of each one, which teachers are dedicated to what they teach and have advanced knowledge in the field, and which teachers painstakingly plan their lessons.