derifatives

Malcolm Gladwell has a piece in the latest New Yorker on what's wrong with our school system, and how to fix it.

Gladwell starts by discussing college scouting, and how difficult it is to predict how well the top college quarterbacks will do in the NFL. For quarterbacks, the NFL game is qualitatively different from the college game: much faster, much more dynamic, much more athletic. The only way to tell for certain that they'll be great NFL quarterbacks is to see how they play in the NFL. Gladwell goes on to suggest that selecting teachers faces similar problems — that we cannot hope to predict in advance how good teachers are going to be. As a secondary example, he uses a financial advising firm, who interviewed 1,000 candidates, offered internships to 49, jobs to 23 of those, and expected roughly half of them to end up making it. In the case of the advising company, it took three to four years of sustained observation to find the actual performers.

Gladwell also makes some points about dynamic range in teaching. If a median teacher covers one year of material in one year (by definition, I suppose), there exist many bad teachers who cover only half a year of material and many good ones who cover a year and a half of material. Teacher effects are a very strong predictor: on average, moving from a 50th to 85th percentile quality teacher is about as good as cutting class size in half. According to one study, if we replaced the bottom 6-10 percent of teachers with median quality teachers, we could close the education gap we have with a bunch of other better performing countries.

Gladwell's suggestions are that we make it much easier to get into the teaching business, eliminating things like required masters degrees which are expensive and have little correlation with performance. He suggests eliminating easy and automatic tenure, rigorously evaluating performers, and paying good performers a lot more.

These suggestions are all fine as far as they go, but Gladwell kind of goes off the rails because he fails to understand some key differences between teaching, football and financial advising. Football has very strong zero-sum and winner-take-all properties: there are a a total of 267 victories each season to divide among 32 teams, and only one team can win the Superbowl. The difference between a world-best performer and an almost-but-not-quite-world-best performer is therefore enormous. It's critical to constantly evaluate whether your quarterback is the best possible rather than merely very very good — the merely very good ones are actually "failures." Financial advising isn't quite as zero-sum, but I posit that there are many more people who want to be financial advisers than there is a need for financial advisers.

Teaching, on the other hand, is a very different situation. Gladwell himself notes that merely replacing the worst teachers with median quality teachers would be an enormous win. And we don't need just a few good teachers, we need a giant mob of them.

I am a firm believer that in nearly all cases, practice and effort can improve skills. It's true for football, it's true for financial advising, and it's true for teaching. In the case of teaching, Gladwell makes a good argument that we have identified some of the skills involved: how good is the teacher at giving rapidly iterated useful feedback, how often is the teacher interacting with the group. Everyone who wants to get better at anything needs to practice and put in effort.

But Gladwell thinks we need to hire four teachers for everyone one we "end up" with, weeding them out and washing them out like financial advisers or football players. I disagree. We need more focus on the skills that make teachers successful, and more incentives for teachers to learn and practice those skills. But we're not trying to find the 30 best teachers, we're trying to teach a whole nation of kids. We're trying to create a situation where every teacher is as good as the 85th percentile teacher is today. Instead of taking a stance that teaching is something that only a chosen lucky few could ever do, let's assume that nearly all teachers can get better with appropriate practice, and that many of them can probably become good enough with the right incentives.

Analogy from my personal life: I am an amateur musician. If my goal is to become a professional classical concert pianist, the appropriate course of action (other than, at my age, seeking psychotherapy) is to spend every waking moment practicing. There is very limited demand for my skills, and I have to be not only very very good, but actually better than almost anyone else. On the other hand, if I want to become a very good piano player, it is sufficient to practice for a couple hours a day, especially if I practice in good ways. I think becoming a teacher is a lot more like becoming a good piano player than a professional concert pianist, and I think our policies should reflect this. So while I agree with Gladwell about relaxing masters degree requirements, rigorously evaluating performance, and increasing pay for performance, I don't think the analogies with quarterbacks or financial advising are very strong.

(Aside: I am no football expert, but Gladwell could check his facts better. One of the lynchpins of his football argument is that colleges generally run the shotgun spread and the NFL doesn't. However, Tuesday Morning Quarterback suggests otherwise.)

(Update: Anna says that attacking Malcolm Gladwell is kind of beating up a strawman.)