Value-added assessment is all the rage since te introduction of Race to the Top.

Before then, everyone understood that teachers, families, school resources and the student herself (or himself) were the determining factors in student test scores.

But RTTT set off a movement to use scores to evaluate teachers, hoping to identify laggards and fire them.

The only problem: VAM is junk science. The low ratings tend to go to teachers of ELL, special education, and troubled kids. The scores, it turns out, measure WHO you teach, not teacher quality.

VAM isn’t working anywhere, yet our nation will squander hundreds of millions, maybe billions, trying to make it work.

Now we hear from a great blogger in Pennsylvania: VAM is sure to be a mess there, as everywhere else.

Junk science is junk science.