Friday, February 10, 2012

Class Size Incentives

There's an interesting story in today's Crimson about a possible rise in "limited enrollment" classes at Harvard.  (See this older Crimson article as well.)  There may, of course, be didactic reasons for limiting the number of students in a class, but there seems to be an impression that there's something else behind this.  A somewhat harsh quote from Harry Lewis:
“My sense is that it’s increasingly thought to be a matter of professorial prerogative to say, ‘to make a better teaching experience for me, I’m not going to teach these students who are paying $50,000 a year to come to Harvard’—and it doesn’t seem right to me,” Lewis said.
Clearly Harry has a point.  On the other hand, from the faculty point of view, Harvard (and from what I know, many other schools) don't generally incentivize teaching larger classes -- which, I can tell you (since my class size doubled from last year), is indeed more work.  If you're not tenured, there may be some incentive to teach a larger class sometime early on -- it shows you're a team player, useful to the department/college, etc.  Past tenure, I'm not sure there's a direct incentive -- although plenty of faculty enjoy teaching, and are happy to teach larger classes at least once in a while.  Without such incentives, isn't limited enrollment understandable (as long as nobody stops you)?

Should a university offer incentives for teaching larger classes?  Perhaps some additional time on teaching leave?  Or direct monetary compensation?  What is the "social contract" between faculty and students regarding when class size should be limited?  Or the less social contract between faculty and their employers, the universities?  How are these questions affected (if at all) by the newly developing paradigm of classes of 100,000+ online?

Challenging questions, I think.


Anonymous said...

At my teaching-focused institution, the type of sections you teach (size of class, is it for freshman non-majors vs. senior majors, is the class brand new or have you done it 20 times before) can weigh heavily on your yearly teaching score from the Dean's office, which directly affects your raise. (Even full professors get scored every year here.) If you get solid evaluations, but only taught upper level small classes, this is not considered all that impressive and you won't get much of a raise. If you teach large intro classes and get really good evaluations, this is considered more impressive and you get more of a raise. This seems to work reasonably well to motivate people to teach a wide range of classes.

Chandra said...

I view teaching large classes as paying the bills. Tuition costs are going up faster than inflation and one cannot be oblivious to that especially at public schools like mine where there is also a sense that we have to educate a good number of the state's students.

Unknown said...

There should be a reasonable "upper bound" on the number of students that participate in a class. It can depend on how mature the audience is, the infstrustructure as well as other unexpected factors (something fascinating that happened just before class).

From my experience as a student, above 200 students teaching a class seems impossible. This number can easily drop to 50 or 60, depending on the factors I mentioned above.

First comment covered be pretty much on incentives. Also, funds for additional grad students, ergo a boost to your research, as a reward for the time you commit in teaching.

Timothy Chow said...

When I was a student, I definitely felt that I had a different learning experience in classes with a small number of students. Certain kinds of personal interaction, not just between the students and the professor but also between students, just don't happen in larger classes.

Of course it's still possible to increase enrollment in a class while keeping the class size down, by requiring the professor to teach more than one section of the class. But I wanted to point out that small class sizes are not necessarily just the result of professorial laziness; they have their own merits.

Anonymous said...

Is the student experience with 40 students that different from 60? What about 90? 120? 150?

15-20 clearly feels different from 40.
5-10 clearly feels different from 20.

I used to teach mostly classes of 40 which increased to 55 and, most recently, to 70. I don't notice a big difference except that I no longer can grade all tests or exams myself (something I used to do for consistency and better feeling for how students are doing when I assign grades).

Michael Mitzenmacher said...

Chandra -- I have a similar point of view. Harvard's paying my salary (by way of student tuition, among other things). They want me to teach something, I should aim to teach it. If I don't want to teach what they want me to teach, maybe I should find another job.

I also agree with others, though, that point out that there may be good reasons to limit class size. In particular, students aren't just paying to get "the classes they want", they're paying for an educational experience, and (at least some) of that experience should be smaller classes and the unique opportunities those classes offer.

Harry Lewis said...

A few comments.

1) When you said "harsh" I thought you were going to quote something else I said in that story ;)

2) There has been far greater growth in students studying CS than there has been in faculty teaching it here. So there is a basic math problem, whether we like large courses or not.

3) I'd like to see any credible research showing that large classes are intrinsically a worse experience than small classes. I believe the K-12 research doesn't support that conclusion very well. Of course in tertiary education "large" takes on an entirely different meaning. By the way, we'd have to define "worse experience" to mean "less educational." I don't particularly care about the other meanings colleges give to that term.

4) By any rational accounting, having ladder or tenured professors teaching small classes is unbelievably costly on a per student capita basis. So it has always been clear to me that large courses are badly underinvested. For a small fraction of what it would cost to split CS 124 (which you are teaching) and have another full professor teach the other section, they should have someone giving you back rubs before and after every class, buying you a nice dinner out with your wife with paid babysitting after every lecture, etc. It wouldn't add up to 10% of what it would cost to clone you. At a minimum the level of professional and TF staff support should be higher -- except of course that we don't have enough TFs, so that means professional staff. But that could be done.

5) I got onto this because I was ticked off after reading an earlier Crimson story. A lot of this story is about misprediction of enrollments, a separate but closely related problem which should be solved through the kind of learning model Stu Shieber's students developed a few years ago, but which for some reason the Harvard administration stubbornly resists.

Timothy Chow said...

Harry Lewis asked for research into the effect of class size on achievement. Although now more than 30 years old, the paper Meta-analysis of research on class size and achievement by Gene Glass and Mary Lee Smith is in my opinion still a good entry point into the literature.