There’s a lot of controversy about the recent teacher effectiveness study highlighted on the front page of The New York Times a week ago. You can read all about it at The Best Posts On The NY Times-Featured Teacher Effectiveness Study. I’ve written two posts about it — “let some of the players with lower batting averages go” and The message is to fire people sooner rather than later.

Now, Michael Winerip at The Times has written an exceptional commentary. Here is how he ends it:

Economists need to find a way to quantify everything. Teachers with high value-added ratings may indeed have long-term positive impacts on students. But it is also possible that teachers who are excellent at project-based education have an even stronger longterm impact and we would never know it because their results cannot be teased out of a million pieces of data.

The danger is that education policy gets driven by teaching methods that can be given a number.

I suspect that Mr. Noyes, my 11th grade Advance Placement American history teacher from 40 years ago, had a low value-added rating. As I recall, no one in our class got a top score of 5; I got a 3. There was no prepared curriculum aligned with the test: Mr. Noyes built the lessons. On any given topic, he would assign us several books that viewed history through different lenses — economics, politics, personality.

I have long ago forgotten the content of those lessons, but Mr. Noyes instilled in us something far more important: the understanding that history does not come from one book. While that idea has served me for a lifetime, I do not believe it is quantifiable.