An issue brief from the Century Foundation by Gordon MacInnes: “Eight Reasons Not to Tie Teacher Pay to Student Test Scores.”

Reason #1: Tying test scores to teacher compensation suggests that teachers are holding back on using their experience, expertise, and time because they are not being paid for the extra effort.

Reason # 2: The standardized tests in most states are lousy and so are the standards they are designed to measure.

Reason #3: The idea of compensating teachers individually in order to differentiate their performance from their school colleagues defeats a principal tenet of good instruction—that teachers need to learn from one another to solve difficult pedagogical challenges.

Reason #4: Most teachers do not teach a grade or subject that is subject to standardized testing.

Reason # 5: Even reliable standardized tests are valid only when they are used for their intended purposes.

Reason #6: A key assumption of using test scores to judge teachers is that students are randomly assigned, first, to schools, and, second, to classes. Neither is true.

Reason #7: State data systems are in their infancy. It turns out that it is harder, is more expensive, and takes longer for states to produce reliable, accurate, and secure longitudinal data on students and teachers than widely assumed.

Reason #8: The rationale for tying tests to compensation is not clear.  …  if teacher compensation does not keep up with inflation because of poor student performance, then teachers will . . . what? Work harder? Dig deeper? Stay longer? There is no evidence that such measures improve instructional practices or student outcomes.

And as Diane Ravitch points out: to tie test scores to teacher evaluation requires a minimum of three years’ data. At then end … what? Fire the “bad” teachers? And replace them with … who? new teachers? There is no precedent for this in any other developing nation.

Read MacInnes’ entire brief here.