How to Grade Teachers
Great teachers matter enormously to the success of their students. While this seems like common sense, it has also been borne out by decades of empirical research: Several studies show that to which teacher a student is assigned makes a huge difference in determining how much that child will learn in a given school year. And many of the benefits of good teachers are more long-lasting. A new study by researchers at Harvard and Columbia, for instance, shows that a student assigned to a great teacher is less likely to have an early pregnancy, is more likely to attend college, and will earn a higher salary as an adult.
In response to such findings, policymakers across the nation are aggressively pursuing policies to address teacher quality. At the federal level, teacher-quality reforms played a central role in President Obama’s Race to the Top program. And several states — including Colorado, Florida, Indiana, Connecticut, New Jersey, and New York — have recently adopted or seriously pursued reforms that would connect crucial employment decisions, such as those regarding salary and tenure, to teachers’ performance (rather than to seniority).
But of all the current reform proposals related to teacher quality, the most fundamental are those that would change the way public-school teachers are evaluated. The reason is straightforward: Any reform policy linked to teacher quality requires first being able to accurately assess teacher performance. It would be impossible to compensate teachers based in part on their performance, or to improve the system’s ability to assign tenure, without an evaluation tool capable of distinguishing between the system’s best and worst teachers.
Unfortunately, the current system for evaluating public-school teachers makes no meaningful attempt to assess the influence that a teacher has on his students’ outcomes. Consequently, just about all of the nation’s public-school teachers are deemed “satisfactory” on their official evaluations.