If you believe that the problem with K-12 education in America is infiltration by gangs of bad teachers who don't give a damn whether their students learn or not, this sounds like a solution. If you believe this, you probably haven't spent much time in an American school. The vast majority of teachers desperately want to see their students learn, but teachers don't control the system. (See Let's stop blaming the teachers!)
But, for the moment, let's talk about "value added" performance evaluation for teachers. Just what standardized test will we use? The New York Times recently ran a story by Michael Winerip pointing out some problems. "For teachers in subject areas and grades that do not have state tests (music, art, technology, kindergarten through third grade) or do not have enough state tests to measure growth (every high school subject), it is the state’s responsibility to create a system of alternative ratings. In New York, that will have to cover 79 percent of all teachers, a total of 175,000 people. The only state tests for assessing teachers are for English and math, from fourth grade to eighth." [Emphasis mine.]
Not wanting to appear "bossy," federal officials have left the nuts and bolts of evaluation up to state officials who are, in general, passing the problem along to local officials. With the exception, that is, of how much the "value added" score should count towards the teacher's total evaluation grade.
"In May 2010, the teachers’ union and department officials, including [NY State Education Commissioner] Dr. King, agreed that student scores on state tests would account for 20 percent of a teacher’s evaluation. In August 2010, Mr. Duncan visited the state union’s headquarters in his Race to the Top bus (he really has one) and told union and department officials that New York had won a grant “because of your collective leadership, your act of courage.” [Emphasis mine.]
'It would take so much time away from instruction to focus on the assessment,' Mr. Infante said."