Chancellor Kaya Henderson, head the of the District of Columbia public school system, recently announced that the district would suspend the practice of using student test scores to evaluate teacher performance while students adjust to new tests based on the Common Core standards.
The District of Columbia public school system was one of the first in the country to evaluate teachers using student test scores. My hope is that others districts around the country will follow the district’s recent move, and that they will ultimately realize that evaluating teachers based on student test scores is an invalid measure of teacher performance.
Chancellor Henderson went on to say that it wouldn’t be fair to use the new tests until a baseline is established and any complications are worked out. That remark alone should be an indicator of why using student scores to evaluate teachers doesn’t work. After all, if student tests were a valid measure of teacher performance, why should the new tests pose complications or need baselines established?
The fact is that using standardized tests to evaluate teacher performance is a political, not an educational, decision. No research justifies the use of such tests for this purpose. In fact, using any standardized test for this purpose is invalid and unreliable. There are just too many extraneous factors.
If we really want to improve teaching, we should look to develop models of effective evaluation rather than pursuing problematic schemes that measure teachers, create disincentives for teaching hi-need students, offer no useful feedback on how to improve teaching practice, and risk driving some of the best teachers out of the profession.
