I'm not saying Seattle's grade-the-graders proposal is worthless. There have to be ways to reward the stars and shed the lemons. Seattle is right to confront these issues.
But across town, the Bill & Melinda Gates Foundation is in the midst of a study of whether it's even possible to reliably score teacher effectiveness. And, if so, what things — experience? test scores? knowledge? teaching style? — are the best measures of a great teacher.
They don't know yet (the results aren't due for a year and half.) My hunch: Teaching — especially good teaching — is far more art than science.And he ends with:
No matter what teacher-testing tools they come up with, they should inform, but not replace, people. In the end a principal should do what managers must do in countless other workplaces: decide who gets promoted and who gets fired. And then take the heat.
It's imperfect. It's hard. That's why there's no formula for it.