The latest skirmish in the escalating education wars came as the New York Times published performance rankings for public school teachers from throughout the five boroughs. The United Federation of Teachers had finally exhausted all legal efforts to block the release. The New York City Education Department released rankings for 18,000 teachers, simultaneously admonishing the media not to use the scores to "label or pillory" teachers. As if.

The rankings themselves came with labels, making the Education Department's admonition seem insincere, irrelevant or both. Once the lists were published, the world knew which teachers the Department viewed as low (printed in alarming red), below average (purple), average (drab grey), above average (pleasant blue) or high (lovely bird's egg blue). The media didn't have to pillory anyone. The Education Department took care of that.

And someone was surely going to get pilloried. Once a "bell curve" methodology is established, someone is going to fall into the lower categories, regardless of actual competence. It's rather like placing the Miami Heat starting five on a bell curve scale. By this measurement, Dwyane Wade is an average basketball player. Compounding this piece of foolishness was the Department's admission that the statistical margin of error was as high as 53%. This means that Wade might be averaging 26 points per game or, well, maybe actually 13. Who knows. Many teachers in apparently "high performing" schools were rated "low" because of this 53% error margin or due to the liability of being on a relatively strong team. This statistical unreliability is only a small part of the problem.

Worse, perhaps, is that the rankings emphasized how teachers improved (or not) from year to year, without regard to where they started. Punishing the basketball analogy, this means that if D-Wade averaged 26 points per game in 2010-11 but only 22 in 2011-12, he would be deemed "below average" when compared with an off-the-bench player at an inferior franchise who raised his production from 8 points per game to 12.

Worst is that the rankings were derived almost entirely from student performance on standardized math and English tests. The correlation between teaching competence and test performance is low, at best, when taking into account wide variations in student ability, numbers of special needs students, socio-economic factors and class size. Therefore New York City teachers are being evaluated, rewarded and punished largely on the basis of factors over which they have little or no control. This will not improve teaching or learning.

Worse than worst is that these measures incentivize lousy teaching even if all the other issues I cite were absent. I have not met a single teacher, public or private, who wants to "teach to the test." While politicians and bureaucrats blather on about accountability and data, teachers all know that there are much more important things to do in a classroom. But they can't do them. There isn't time.

Among the actual problems in American education is the sad reality that good teachers are leaving the profession in droves and that bright young folks are discouraged from entering it. In the powerful movie Race to Nowhere the most poignant moment, for me, was watching an energetic, charismatic young woman dissolve in tears as she described her decision to abandon the profession and the children she loved because she simply wasn't allowed to teach and could no longer bear it.

And why would anyone in her right mind want to be a teacher? Low pay, long, thankless hours of preparation and grading, ever-larger classes and demanding parents. Sounds like a dream job, eh? And now, at least in New York City, an opportunity to be publicly humiliated in the New York Times on the basis of flawed data with a 53% margin of error. Shall I sign you up?

This data-driven drivel is sucking the heart out of teaching and learning. If politicians or policy makers want to know who the good teachers are, they might spend some time in schools and watch the magical ones at work. The kids know who's good. Any principal worth her salt knows who's good. Teachers don't need metrics-driven scolding or public humiliation. They need good facilities, small classes, books and materials, professional development and moral support. This takes money, but all the big talkers refuse to spend any. It is, as I have sometimes quipped, as though policy makers think Hansel and Gretel will get stronger just by being weighed more often.

But given what's happening in New York City and many other places around the nation, pretty soon there just won't be any teachers left to kick around. What a tragedy.

