I certainly understand teachers’ angst when it comes to being evaluated based on their student test scores. Being evaluated is not a fun experience but when that evaluation is also based on the performance of others it makes the process that much more stressful. To make matters worse there appears to be a number of misconceptions regarding exactly how test scores are used to evaluate teachers.
A USA Today editorial by Alexandria, VA high school teacher Patrick Welch is an example of some of the misconceptions many teachers have about using tests to evaluate them. Mr. Welch’s observations are far from unique. I have heard similar misconceptions from other teachers and even researchers which makes identifying such misconceptions all the more important.
New teacher evaluation systems more accurate than previous evaluations systems
First of all, it must be recognized that there is no such thing as a perfect evaluation system in any profession. So while even the best evaluation systems will certainly identify some truly effective teachers as ineffective it doesn’t mean teachers shouldn’t be evaluated at all. However, evaluation systems should be designed to minimize the chances of such occurrences. As explained in our Building a Better Evaluation report, there are a number of tools available to make evaluations more accurate.
Test scores can accurately measure a teacher’s performance when used with other measures
Mr. Welch cites research showing the inaccuracies of using test scores to evaluate teachers. For example, some teachers are identified as effective using one test but identified as ineffective when based on a different test. While the research he cites is sound, they do not tell the full story because they are based on using one test to measure a teacher’s effectiveness. In no state that requires teachers to be evaluated based on their impact on student achievement is a teacher ever evaluated based on one measure. In fact, every state requires at least one measure of instructional practice such as classroom observations to make up at least half a teacher’s evaluation. Even in states where half of the teacher’s evaluation is based on student achievement measures, those states require multiple measures of student achievement, not just results from the state assessment.
Teachers are not penalized for teaching lower-performing students
Keep in mind when evaluating teachers based on measures of student achievement it doesn’t mean that teachers are evaluated based on their students’ overall scores. Instead teachers are evaluated on the growth of their students’ test scores from one year to the next. So teachers are evaluated based on the growth their students made while in their teacher’s class.
This is something Mr. Welch appears to misunderstand. This is typified by his story about how he improved the test scores from his Advanced Placement class by encouraging lower-performing students to dropout. He also quotes Jesse Rothstein who said of ranking teachers based on test scores “rewards or penalizes teachers for the kids they teach, not just for how well they do it.”
Fortunately for teachers and students teaching lower-performing students will not likely hurt a teacher’s evaluation. A well designed teacher evaluation system will not penalize teachers for teaching the hardest to teach students. Even if student test scores are a significant factor in the teacher’s evaluation. That is because teachers are evaluated based on the growth their students make from year to year and not on their overall achievement.
Truly rigorous evaluations will assess student growth using a value-added model (VAM) that takes into account each students prior achievement and other background factors to determine if they made as much or more growth than if those students had an average teacher. By making such comparisons, teachers are evaluated based on the quality of their instruction not on the students assigned to their class that particular year. So while Mr. Welch would be correct to worry about being evaluated on his students’ overall test scores, this is not what is happening across the country— although a report CPE will release later this summer finds teachers in some states are more likely to be evaluated accurately than in other states.
Recent research shows teachers can be evaluated accurately
While no evaluation system is perfect and all states should continually update their systems to make them more accurate, the Measures of Teacher Effectiveness (MET) study shows that combining measures of student growth with measures of instructional practice to evaluate teachers provides a reasonably accurate measure of a teacher’s true effectiveness. And when the results are looked at over multiple years they are a more accurate measure.
So while it is understandable that Mr. Welch and many teachers across the country are apprehensive about being evaluated in part on their student test scores, such anxiety should be put at ease knowing they are being evaluated based on the growth their students make and not on the overall performance. And those teachers who are evaluated using value-added scores should have even less anxiety as they provide the most accurate measure of a teacher’s true effectiveness especially when combined with measures of instructional practice. – Jim Hull