PHY 302: Classical Mechanics I

This semester I am taking a new approach to teaching my Classical Mechanics I course. In the past this course has been entirely lecture-based, although I have a lot of one-on-one interaction with my students outside of class because it is a class taken only by physics majors (and there aren't that many of them). I have also used computational problems to get them some hands-on computing experience while they learn classical mechanics (hopefully a paper describing this aspect of the class will soon be published in the American Journal of Physics). But this semester I am mostly abandoning lecture. Only about one fourth of our class meetings will be lectures, and these will be devoted almost exclusively to computational demonstrations (where I show them how to use computation to analyze the dynamics of classical systems). At least part of these "lectures", which are given in the computer lab, are given over to the students running some computations themselves.

For another fourth of our class meetings I am using a few of the Intermediate Mechanics Tutorials developed by Brad Ambrose and Michael Wittman. Tutorials are worksheets that lead groups of students (my students work in pairs) through a series of questions that challenge misconceptions and elicit insights into important physical principles. These tutorials are then followed up with homework assignments that are designed to test student understanding of the tutorial material and build on the insights gained in the tutorials. Typically a pretest is given before the tutorial. I have found that we often need the full 75 minutes of the class period to complete the tutorials, even though they are allegedly designed for a 50 minute class.

The remaining half of the classes are devoted to student presentation of homework problems. This is a take-off on the Moore Method, which was a method for teaching mathematics developed by R. L. Moore at the University of Texas. The strict Moore Method forbids students from working together or using textbooks - they must prove theorems on their own and present their proofs in class. I deviate heavily from this strict version, as my students definitely use their textbook and can discuss the problems with each other (but not copy). Still, the focus of the class is the students presenting their solutions. Other students are expected to critique the solutions that are presented. The presentations are evaluated on content as well as on quality of presentation. Each assigned problem is presented by a student and all students must turn in written solutions for every problem. I've been guided by all of this by my fellow physicist Chuck Lane who pioneered this approach in our department last year.

I'm only halfway through the semester, but so far I would report both great success and some disheartening results. The disheartening thing was that I started with 11 students enrolled in the class but 5 of these withdrew because they thought the workload would be too great. However, the remaining 6 are doing quite well. I was very impressed with the performance of the class on the first exam. The homework presentations have improved steadily, both in terms of correctness and style. This has also led to similar improvements in the written homework (which has not generally been the case when I've taught this course in the past). The tutorials have also been great - I plan to use them more systematically the next time I teach the course. And I'm still doing the computational problems, which seem to be going pretty well.

The mixture of tutorials and homework presentations seems to give a nice balance to the class. There isn't an adversarial environment, because a lot of the time they are working together on things. One problem is that it is hard to get the students to really critique each other - they think they are going to hurt someone's feelings. And I am probably a bit to willing to jump in and give my own critique if the other students aren't willing. But they (and I) are getting better about this. I try to prod them when I can tell they want to say something. I periodically remind them that they aren't helping their friends by failing to point our errors in their solution. I know its wrong, so their presentation grade will still suffer, and if the errors aren't pointed out then their written solution will likely get a low grade as well. Pointing out the error will help them fix it and avoid a lower grade. They aren't totally convinced, but I'll keep working on them.

In summary, it's been a very experimental semester but it seems to be going very well. I will tinker with the balance of presentations, tutorials, and lectures but I will probably not get rid of any of the three (although I feel I definitely won't increase the lectures).