As mentioned in the previous post, there has been a lot of interesting stuff written about education in the last week or so, much of it in response to the manifesto published in the Washington Post, which is the usual union-busting line about how it’s too difficult to fire the incompetent teachers who are ruining our public schools. Harry at Crooked Timber has a good response, and links to some more good responses to this.
I’m curious about a slightly different question, though, which is in the post title. There’s a lot of talk about how incompetent teachers are dragging the system down, but you don’t see many citations of useful data about how many of these school-killing teachers there really are.
So, the question is, what fraction of public-school teachers are genuinely incompetent? That is, how many of them are so bad that they ought to be driven out of the profession altogether? Obviously, you would expect something like half of them to be “below average” by some measure, but that’s going to include a lot of people who aren’t all that bad, but got a bad class, or had a bad year. I’m talking about the left side of the bell curve (if it even is a bell curve– that’s not necessarily the case)– the ones who are really bad, year in and year out.
Anecdotally, I suspect the percentage is pretty small. From my own school days, I can only think of one teacher I had who, in retrospect, I think was genuinely doing a bad job (and I’m not sure whether that was something that would show up in test scores), and a couple of others who had a really bad reputation. That’s out of around a hundred teachers in the district, so you’re looking at maybe 5% incompetents.
Now, I had the advantage of having a father who taught in the district, and could steer me to the better teachers at each grade level, so it may be that I missed some really bad people. But again, my father taught in the district, so I also get to hear his impressions of his colleagues, and I don’t think the number of bozos gets all that much bigger based on that.
Does that mean that I only had one or two teachers I disliked? No. There were plenty of other classes I didn’t care for, but with the benefit of hindsight, I can say that a lot of those were just a mismatch of styles, with the teacher doing something that worked for the rest of the class, but didn’t work for me. I’m talking about people who look bad even from my current perspective– whose control of the classroom was erratic to nonexistent, whose assignments were pointlessly tedious or ridiculously easy, who taught to a test and didn’t attempt to stretch their classes at all.
Is this just an illusion caused by a privileged position? Enh. Maybe, but I doubt it. I think it was certainly the case that better teachers got assigned to better classes (at the high school level, some of the people who had the reputation of being really bad taught non-Regents classes), but I don’t think that was a huge part of it. And it’s certainly not a matter of going to an elite district– this was a public school in a rural part of New York State, not some wealthy suburban district flush with cash.
This does point to a problem with anecdotal experience, though, which is that the limited number of teachers a given student sees tends to magnify the perception of incompetence. That is, while there are 100-ish teachers in the district, as a student, I only took classes from maybe 30-40 of them over the 13 years I was in school. Which means that a person who wound up with one really bad teacher would think, based on their experience, that the fraction of incompetent teachers was significantly higher– a single bad teacher in a district of 100 teachers is 1% of the total, but 3% of the sample of 33 teachers that a single student sees.
Anyway, this isn’t data by any stretch, but I’d be interested to see some real data on this topic. What fraction of teachers are genuinely bad at what they do, but hanging around because they’re impossible to fire?