Much of the coverage of value-added measures for judging teacher effectiveness assumes that such measures would falsely identify decent teachers as being ineffective. That's certainly an area of concern, given the fact that the estimates seem unstable, especially if they're calculated over just one year of data.
But is there a reason to think that the data could help other teachers make the case that they are effective? The experience of some union affiliates with value-added suggests that is a possibility.
For instance, while covering the NEA Representative Assembly this summer, I spoke in depth with the current and former presidents of the Tennessee Education Association, respectively Gera Summerford and Earl Wiman, about the state's win in the Race to the Top program. That federal competition put a premium on including student-achievement information in teacher evaluations.
You may remember that Tennessee has had value-added data for more than a decade, and until recently, it was an optional but not mandatory component of teacher evaluations.
According to Wiman, over the past decade, the union has actually used information from that state's value-added system to save teachers' jobs during tenure and dismissal hearings. In other words, the information showed that those teachers did make a difference for kids, and effectively served as a type of check on principals.
Under a law passed to position Tennessee for RTT, value-added will make up part of a teachers' evaluation, in addition to locally developed growth measures and observations. About this new system, Ms. Summerford said, "I"m confident it isn't something any teacher should be afraid of. I think the data will surprise us."
The union did draw the line at a mandatory connection between the scores and teacher pay. That element will be bargained locally by districts receiving dollars through RTT.
And the union leaders did say that there's a need to make sure that all the data are accurately matched between teachers and students, which has apparently been a problem in certain instances.
Generally, neither of the two union leaders was exactly sanguine about the Race to the Top. But their objections were rooted more in the program's overall prescriptiveness than in the value-added piece.
"I'm still hopeful we can enact some true reform around this," Ms. Summers said about RTT, "but I'm not confident it will happen."