A recent post over at Kevin’s Walk, one of my regular stops, was about teachers and teacher effectiveness. He cites the following paragraph from this article in The New Yorker by Malcolm Gladwell:
Eric Hanushek, an economist at Stanford, estimates that the students of a very bad teacher will learn, on average, half a year’s worth of material in one school year. The students in the class of a very good teacher will learn a year and a half’s worth of material. That difference amounts to a year’s worth of learning in a single year. Teacher effects dwarf school effects: your child is actually better off in a “bad” school with an excellent teacher than in an excellent school with a bad teacher. Teacher effects are also much stronger than class-size effects. You’d have to cut the average class almost in half to get the same boost that you’d get if you switched from an average teacher to a teacher in the eighty-fifth percentile. And remember that a good teacher costs as much as an average one, whereas halving class size would require that you build twice as many classrooms and hire twice as many teachers.
These conclusions are based on teacher effectiveness research; more about that shortly.
Gladwell goes on to make the case that you can’t predict teacher effectiveness, and appears to recommend, based on these “facts”, that teacher education as we know it be eliminated and replaced by a “sink or swim” system that he calls an “apprenticeship” model: we put anyone in a classroom that shows up with a bachelor’s degree in hand (having previously made the point that degree doesn’t predict teacher effectiveness any more than having a teaching credential, he still isn’t prepared to dispense with it), and see who’s successful and who isn’t. The professions he compares to teaching, on which he is in part basing his recommendations, are quarterbacking in the NFL, and financial advising (because, he says, you can’t predict success for them either.)
This kind of interpretation and use of the research to make policy always makes me nervous. In this case, there are a number of issues, having to do with 1) the research itself, 2) his misapprehensions of both teacher education and of the teaching profession at the macro level, 3) the ways in which teaching is simply not like any other profession or occupation out there, and 4) his policy recommendations. Today I’ll tackle only the first.
Teacher effectiveness research:
There are two huge problems with the teacher effectiveness research upon which Gladwell bases his conclusions: first, the crudeness of the measures used, and second the lack of control of other factors.
Most teacher effectiveness research uses such measures as type of degree (some use GPA at graduation) or whether or not the teacher has a teaching credential (some compare types of teacher ed programs or types of credentials and relationship of credential to what the teacher is teaching) as the predictors, and standardized test scores of their students as the outcome measure. These are used because the information is widely available for large numbers of teachers. And, as he said, the results of this research overall have been inconclusive.
Most of us in the ed biz believe that the primary reason this research has been inconclusive–that is, has not yielded reliable predictors of teacher effectiveness–is because of the crudeness of the measures used. For the “predictor” varialbes (degree, GPA, credential), the “signal to noise” ratio is too poor to provide useful information. The unreliability of those measures, and the enormous variation hidden within each, practically guarantees that no conclusive results will be found.
And then there are all the usual issues with using standardized tests as measures of student learning. I know they are driving the education system these days–but where are they driving it to? I’ll spare you my own diatribe and refer to you to Alfie Kohn’s book instead (he’s very leftie-radical–even I don’t entirely agree with him- -but he’s got his facts straight).
And finally, there’s the issue of controlling for other variables. Including lots and lots of teachers, and using sophisticated statistics, is supposed to take care of that, and maybe it does, but then again maybe it doesn’t. It’s the signal-to-noise thing again. If there are indeed valid predictors of teacher effectiveness, but some push the data one way and others push it another, the overall result will be “no result”. Such interaction effects are very common in research on human beings. For example, there is research that indicates that the nature of the teacher education program does make a difference to teachers’ effectiveness. That is, some programs are very effective (and we know something about the factors that tend to make programs more effective), and some are less, in terms of turning out effective teachers. But if all you look at is whether or not the teacher completed some teacher ed program somewhere, you won’t discover that.
There’s also the reality that a given teacher may be effective in one setting and not in another. To use the quarterback comparison Gladwell uses: kinda like Brett Favre was unimpressive with his first NFL team (sorry guys, I don’t know what team that was–I’m no football fan), but with the Packers he became one of the best in history. And some settings work against any teacher being effective. Exceptional people do occasionally rise above such conditions–but the point is that they are exceptional (say, less than 0.1%). If teachers are to be evaluated and eliminated based on measures of student learning, God help those who are unfortunate enough to be placed in such settings–most won’t have a prayer of surviving. All of this militates against using teacher effectiveness research in it’s current state to draw the policy conclusions that Gladwell promotes (or any other policy conclusions either, for that matter.)
Life is busy. Check back in a couple of days for Part II:
The nature of teacher education and of the teaching profession
Great insights. Looking forward to Part 2.
My own take on standardized testing: it makes some sense up to and through high school, after which it makes no sense at all, whether a student goes on to a liberal arts college or a trade/vocational school.
I think a legitimate case can be made for knowing certain basics (language arts, history, math, science, art, music, etc.), not merely for the sake of personal enrichment but also for us Amurricans to stay internationally competitive.
I also think Gladwell is correct to note that certifications don’t always guarantee that a person will be a good teacher. I’ve known certified English teachers who are shit in the classroom, and uncertified ones who have a natural gift for effective connection, communication, and transmission of skills and knowledge.
In all, I think there’s a middle ground somewhere. On the one hand, becoming slaves to standardization leads to mediocrity and stultification of both teachers and students; on the other hand, having no standards at all creates an academic Wild West. I’m no Spockian: I think grades and standards have their place; they help us structure our expectations and force teachers to think in terms of observable results– behavioral objectives as opposed to cognitive objectives (which are more appropriate at the university level, I think). At the same time, having seen the over-rigorous Korean system up close, I think we in the West do well to continue stressing the less easily quanitifiable aspects of education– teaching creative and logical thinking, skeptical inquiry, etc.
I admit my perspective may be biased by the fact that I’ve been a language teacher for several years, and have spent most of that time dealing with lower-level students.
Rock on,
Kevin
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“quanitifiable “?
Yikes– “quantifiable,” I mean.
Kevin
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[…] December 14, 2008 by addofio (Continued from the previous post.) […]
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OK, having shoved Part 2 out the door, I can now give your comment the attention it deserves.
It looks like I will tackle the standardized test issue in Part 3, so won’t say much about it here. My personal concerns circle around 1) what they include and don’t include–they tend to test what’s easy to test rather than what’s important, and use items that distinguish between people rather than testing “what everyone should know” (virtually the definition of norm-referenced tests); 2) high-stakes use of standardized test results, particularly in conjunction with 3) relying exclusively on standardized tests for high-stakes measures. The combination of these three is having extremely pernicious effects on schools these days, and I see no reason to believe extending it to other populations–university students, teachers–would be done any better than it’s being done in K-12. But that seems to be the wave of the future.
You say “Gladwell is correct to note that certifications don’t always guarantee that a person will be a good teacher.” If you’re looking for a guarantee, definitely you will always be disappointed. Even if a teacher is highly effective by Gladwell’s standards one year, there is no guarantee that s/he will be equally effective, or even effective at all, another year. Life happens, and tends to affect one’s teaching. Students change, and we are more effective with one group than another, because there are definitely student-teacher interaction effects (in the statistical sense). Rather the question is whether a person selected on a given basis is more likely to turn out to be effective than a randomly selected person.
However, that’s not really the issue, is it? What we want is a way to screen out the worst, the really ineffective teachers. We aren’t ever going to be able to staff all the schools with those 85th percentile teachers Gladwell refers to–there will never be enough of them. But we should be able to do better than we are now. I just don’t think untrammelled (I bet I didn’t spell that right) free-market style competition based on students’ standardized test scores is a reasonable way to get there.
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