Absolute Must Read

I don't use that phrase very often; then again, Bruce Baker doesn't often get a large op-ed space to explain why using test scores to evaluate teachers is an insanely bad idea:

Reformers also point to studies showing that teachers’ value-added scores are the best predictor (albeit a weak and error-prone one) of a teacher’s future value-added scores – a self-fulfilling prophecy. 

These arguments are incredibly flimsy. 

In response, I often explain that if we lived in a society where people walked everywhere, and a new automotive invention came along, but had the tendency to burst into a ball of flames on every third start, I think I’d walk. 

Now is a time to walk! 

Some innovations just aren’t ready for broad public adoption — and some may never be. Some, like this one, may not be a very good idea to begin with.

I won't quote any more because you really have to go read the entire thing. Bruce has the ability (like Paul Krugman) to take complex statistical ideas and explain them in a way a layperson can understand.

So print out his op-ed, and put copies on the staff room tables at your school. This is important.