Nobody would ever advocate making personnel decisions through public posting of evaluations in the newspaper. The public release of value-added scores for more than 12,000 New York City teachers, set for Friday morning, should not be taken as a model for how to run the human resource departments of the schools. But that is not what is going on here. The public release of these ratings — which attempt to isolate a teacher’s contribution to his or her students’ growth in math and English achievement, as measured by state tests — is one important piece of a much bigger attempt to focus school policy on what really matters: classroom learning. A key element of this effort is developing evaluation systems that identify both the highly effective and the highly ineffective teachers and administrators — and then actually uses that information to make personnel decisions. To understand why the release of this data makes sense, you must step back and see the intense, broader battle underway throughout the nation. The fight is between those who want to improve the schools and those who like the system as it exists today. Those who want to preserve the status quo have historically had the upper hand. For generations, they have been able to control policy change by focusing attention on the adults in the schools through the contract bargaining process, through labor laws in the legislature and through a supportive media environment. This political balance has, however, taken a sudden turn. Within the last few years, a surprising number of states have revisited the idea of teacher tenure based solely on a couple of years on the job and not on any true evaluation of the teacher’s contribution to students’ learning. There has also been valuable movement to finally begin to base personnel decisions, including both rewards and dismissals, on the basis of real measures of teacher quality. In each of these instances, the development of a rigorous and comprehensive evaluation system is essential. The sorry state of evaluations in the schools has been known for some time. The perfunctory evaluation in which 99% of the teachers are excellent — or, in New York City, 97% are deemed “satisfactory” — fed a system that defied ever removing a teacher because of ineffectiveness. When pressed, everybody in the system nodded knowingly and said sanctimoniously, “we need to develop a better evaluation system.” That agreement led to endless numbers of meetings and statements that said “we must do better.” But the reality of the status quo continued. With the development — finally — of better measures of student learning that came from tracking achievement across grades comes the ability to see where success and failure reside. Turns out, many teachers are doing a fantastic job. But some are doing lasting harm to their children. For them, mentoring and professional development aren’t enough. They must find a different line of work. Contrary to what Bill Gates argued in yesterday’s New York Times, the release of value-added scores of teachers is not a way of shaming the ineffective teachers. It is a prod to insisting that teachers who harm their children should finally be removed from the classroom. Everybody who has looked at the problem agrees. Evaluations should not be based exclusively on test scores but should — as a new agreement in New York affirms — use a combination of evaluation methods that include test scores and other observational methods. The issue raised by the release of value-added information is how quickly and how assuredly we get there.