The Gates Foundation has been undertaking a multi-year study of teacher effectiveness, trying to learn why some teachers' students excel and others don't. How can you evaluate teachers? Should you just look at test scores?
Preliminary findings from the Gates study suggest that there may be one underused approach: ask the students (as highlighted in this Minneapolis Star-Tribune article).
The Gates study had students watch teachers explaining various concepts. The students were asked about the teachers' effectiveness, and were also tested.
It turns out that, as Justice Potter Stewart once said of obscenity, students know effective teaching when they see it. The study also found that a teacher's past success in raising student achievement on state tests is the best predictor of doing so in the future, and that the teachers who demonstrate the best value-added scores on state tests are rated as most effective by students in explaining concepts.
It's a fascinating finding, and suggests that the so-called 360 degree feedback model, in which a person is evaluated by everyone he or she works with, could have some merit in education too. In general, teachers are mostly evaluated by principals, but this suggests that student feedback on effectiveness can also be meaningful.