The Role of Textbooks

Inside Higher Ed has an op-ed piece up urging faculty to abandon textbooks:

Here’s a statement with which everyone can agree: College instructors cannot assume that students come to their classes in possession of basic knowledge. Now here’s one sure to generate some controversy: In many cases textbooks deter the pursuit of knowledge more than they help it. The sciences may be different, but at least in the case of the humanities, most of us would be better off not assigning a textbook.

He goes on to make a strong case for abandoning history textbooks in favor of monographs, based on both the high cost to students and the fact that most history texts are deadly boring.

Both of those arguments apply to a lot of science textbooks– they’re usually hard to read, and always expensive– but it’s hard to see how to get away with abandoning textbooks in science.

For one thing, hardly anybody publishes monographs in the sciences. This is a recurring issue in discussions of how to measure scholarly productivity (how many Physical Review Letters equal one book?), but more important for this discussion is the fact that there simply aren’t any more readable scholarly works out there that are accessible to students. If you want to abandon traditional textbooks, you’re pretty much on your own.

The bigger issue, though, is that textbooks have an important place in the sciences. A good textbook will have step-by-step derivations of important results, presented at a level of detail that’s hard to match in a lecture. There are very few things in this world that are more soul-crushingly boring than watching somebody do algebra on a blackboard, and lecture time is better spent on working through the implications of the important results than going through fiddly details of algebra.

A properly written science textbook will serve as a valuable reference work in a way that a history textbook probably will not. Science textbooks contain additional examples and detailed derivations that go beyond what can easily be covered in class, and those can come in handy down the road. I still have all of my graduate textbooks in physics, and many of my undergrtaduate books, and when I’m prepping a new class or considering a new research problem, I make frequent use of them.

(Sadly, many students don’t really understand this point, and sell their textbooks back to the bookstore before the ink is dry on their final exams. This is a horrible, horrible idea for anybody who seriously plans to pursue a career in science– those books will come in handy down the line.)

Of course, following a textbook too closely creates its own set of problems. The single worst class I had in graduate school was taught by a professor who basically read Shankar’s quantum mechanics textbook to us– one of my classmates used to “take notes” by putting a check mark in the margin next to each equation as she wrote it on the board. Not only was this the dullest possible way to lecture, it was horrible when it came time to do problems, because the lectures and the book were absolutely identical. There was nothing presented in the lecture that you couldn’t find in the book, which meant that the book could not be used to shed additional light on the lectures, and the lectures did nothing to illuminate the discussion in the book.

When I teach, I try to avoid following the textbook treatment too closely, in large part because of that experience. If anything, I probably go too far in the other direction– my lecture notes often bear very little resemblance to the treatment presented in the textbook, and I’ll often cover topics in an entirely different order than you see in the book. I try to explain this to the students, pointing out that if they don’t like my version, they may find the discussion in the book more helpful, but I’m not sure that it gets through.

(I also end up doing a lot of jumping around because of our weird academic calendar– we’re on trimesters, which means we’re supposed to try to cover a semester’s worth of material in only ten weeks of class. In practice, this requires us to pick and choose topics, and occasionally skip whole chapters worth of material.)

I have taught without a traditional textbook once, for the Quantum Optics class I did last spring (you can find a lot of my lecture notes here). I couldn’t find a good traditional textbook at the level I wanted, so I had the students read a more conceptually oriented book, and covered a lot of the mathematical treatment in my lectures. It wasn’t all that bad, but I wasn’t entirely happy with the experience. Since the class ended, a textbook at the right level has been released (Quantum Optics by Mark Fox, from Oxford University Press, part of their Masters Series), and when I teach the class again, I’ll use that instead.

The Inside Higher Ed piece suggests that a lot of history material is available online, and that those free resources can serve as an alternative to expensive textbooks. I have a hard time imagining using something like hyperphysics in lieu of a textbook, though, so I think we’re pretty much stuck with heavy and expensive textbooks in the sciences.