For parents of students in the “average” city teacher’s class, learning the teacher’s rating may not tell them very much, Chancellor Joel Klein wrote in a letter to principals today.

In his email, Klein explained the city’s decision to release teachers’ effectiveness ratings and the teachers union’s move to block this from happening. He noted that the ratings, which measure teachers against estimations of how much their students’ test scores ought to rise, would be most useful in identifying very high and low performing teachers. He wrote:

One indication will never tell the whole story, and sometimes it is hard to discern definitive evidence from data alone — such as with a teacher who is “average” according to these numbers, for example. But where teachers have performed consistently toward the top or the bottom, year after year, these data surely tell us something very important. Namely, we need to retain and reward the great teachers, and we need to develop the low-performing teachers. And those who don’t improve quickly need to be replaced with better-performing teachers.

Klein’s full letter:

Dear Colleagues,

As you have likely heard or read, several media outlets recently issued Freedom of Information Law (FOIL) requests to the City, requiring the Department to share the Teacher Data Reports we provide schools and teachers in grades 4 through 8 each year. These reports use a method called “value-added data” that seeks to predict student performance based on factors outside of a teacher’s control (high levels of poverty, for example), and then determines whether a given teacher’s students exceeded or fell short of these predicted examination scores (teachers may always access their reports at http://schools.nyc.gov/Teachers/TeacherDevelopment/TeacherDataToolkit/GetYourReports/default.htm). By controlling for factors beyond a teacher’s control, it is the fairest system-wide way we have to assess the real impact of teachers on student learning. And while the City’s particular value-add method is not etched in stone, this is why the State passed legislation this spring, endorsed by the teachers’ unions, committing to using value-added data for all teachers. It is also why value-added data is increasingly being used throughout the nation as part of a comprehensive system of teacher evaluation.

In the past we have provided the numeric value-added data to the press with no indication of the identity of individual teachers. I am writing to you today because media outlets, prompted by similar data being published by the Los Angeles Times, have requested the names of individual teachers, not just the statistics. As it is the City’s legal interpretation that we are legally obligated to provide the media this information, it is our intent to provide the data as requested.

In the time since we informed the UFT that we intended to comply with the FOIL request, the union has sued the City to prevent the release, and we have agreed to delay any release until at least November 24, when a court hearing will be held. So no data have yet been released. But I want to make sure that, as you read about these events in the newspapers, you understand the circumstances and you understand my view on the issue overall.

Our most important task is to ensure that every one of our students has a great teacher. It is critical, therefore, that when we have indications of a teacher’s proficiency, we use that indication to do what’s right for kids. One indication will never tell the whole story, and sometimes it is hard to discern definitive evidence from data alone —such as with a teacher who is “average” according to these numbers, for example. But where teachers have performed consistently toward the top or the bottom, year after year, these data surely tell us something very important. Namely, we need to retain and reward the great teachers, and we need to develop the low-performing teachers. And those who don’t improve quickly need to be replaced with better-performing teachers.

Secretary Arne Duncan last week said it best when he said, “I give New York credit for sharing this information with teachers so they can improve and get better.” More than anything, these data demonstrate that we need a better, more comprehensive system of evaluation than the one we have now. That’s why the State legislature and the unions supported an evaluation system that uses value-added data. Now it’s time that the DOE and UFT together build a new system that gives teachers an honest sense of how well they’re doing and how they can improve.

In the end, this is about real people. On one hand, for too long, parents have been left out of the equation, left to pray each year that the teacher greeting their children on the first day of school is truly great, but with no real knowledge of whether that is the case, and with no recourse if it’s not.

But this is also about teachers. They take on the hardest work there is, and they deserve our respect. If anyone sees these data as an opportunity to scapegoat public servants, that is a mistake. Doing what’s right for children means making hard decisions; it has nothing to do with personal attacks.

We’ve made huge strides for our kids over the last eight years. That’s because we’ve been willing to face hard facts. It’s also because we have made kids’ best interests our shared priority. My hope is that we approach this issue with both of those thoughts in mind, ensuring fair treatment for adults, but always keeping children first.

Sincerely,

Joel I. Klein