Using test-score gains is a lousy way to rate teachers

Published in the New York Post, June 6, 2013
The Issue: The new teacher-evaluation system, which will take into account student reviews and test scores.

[New York City has decided that “40 percent of a teacher’s grade will be based on her or his students’ performance.” (“New teacher evaluation plan …, “ June 2).]

 Test-score gains should not be included at all. Studies have shown that rating teachers using test-score gains does not give consistent results. Different tests produce different ratings, and the same teacher’s ratings can vary from year to year, sometimes quite a bit.
Using test-score gains for evaluation encourages gaming the system, trying to produce increases in scores by teaching test-taking strategies, not by encouraging real learning. This is like putting a match under the thermometer and claiming you have raised the temperature of the room.
We are all interested in finding the best ways of evaluating teachers, but using student test-score gains is a lousy way to do it.

Stephen Krashen

published: http://www.nypost.com/p/news/opinion/letters/worthless_teacher_grades_dubious_GVEim7TZh9TaxUaQkwZ7OP