OK, it's not really a full post-mortem, because I haven't graded the final exams yet, but I wouldn't tell you about those, anyway. Still, I wanted to take a moment to reflect on the past term, which was my first teaching introductory mechanics on the Matter & Interactions curriculum.
On the whole, I continue to like the approach. I like the way that the book focuses on the major physical principles-- the Momentum Principle, the Energy Principle, the Angular Momentum Principle-- because those are the real take-away message from introductory physics. I also thing it's good that the class doesn't look like high school physics all over again, but forces students who have had a good high school class to take another look at the same material, rather than just falling back on what they've done before.
Of course, it's not all flowers and happy bunnies...
As much as I like the focus on big principles, I found that the text was awfully short on the sort of straightforward problems and examples that students need to practice on. I used WebAssign to assign homework nightly, but there were times when it was awfully difficult to find useful problems. There are great, detailed, realistic end-of-chapter problems, but it's a big jump from the discussion in the text to those problems. some sections covering important example problems had no exercises at all, while other sections had tons of examples, on topics that were too curriculum-specific to be generally useful.
Chapter 9, on collisions, was particularly bad in this regard. There is really only one general problem about elastic collisions, asking students to find a general solution for an elastic collision with a stationary target. That's a hard problem for them, even when they get some problems with actual numbers to practice on; without detailed examples, it's pretty hopeless. And I would say that the techniques involved in doing elastic collision problems are really crucial for future physics classes-- the whole idea of getting constraints from multiple physical principles, and solving systems of equations to find multiple unknowns is key to a lot of what comes later.
Some of the other omissions are more of a mixed bag. There's relatively little time spent doing vector problems using magnitudes and angles, which isn't great, but then again, I can't say I missed the iconic block-on-an-inclined-plane problems all that much. Likewise the endless variants of projectile motion.
The first time through a new curriculum is always a little rocky (I'm glad I have tenure...), and I think the next time I teach it will go a little more smoothly, now that I know what to expect. I'll go back into old exam questions and Halliday and Resnick to find practice problems to fill in the gaps, and I'll know where I need to spend more time on in-class examples.
Some other issues with this edition of the course have less to do with the book than with local constraints. We teach on a trimester system, but the engineering students who are the main audience for the class only take two terms of physics, rather than a full year. They have certain expectations of the classes, so we're forced to squeeze the curriculum in ways that the authors never intended-- we skip Chapter 7 (on quantization) completely, and rush through Chapters 8 and 9 to end with Chapter 10, on angular momentum. This has the unfortunate effect of putting the hardest material of the class in the last week of class, just at the point where everybody's nerves are completely shot. Were we working with a semester system, Chapter 10 would come with three weeks to go, and there would be time for students to get more comfortable with angular momentum, and we'd end with the less intimidating material on basic thermodynamics.
I'm not entirely happy with the way this term went, but a lot of that was just the shakedown cruise effect. If I teach this class again next year, I expect things will go more smoothly; in fact, I look forward to taking another pass through this material. And given how sick I was of intro mechanics before this year, that's really saying something.
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Did you incorporate vpython and computational stuff? How did that go?
Even if it's not all bunnies, there's some bunnies, right?
I used M&I for one quarter in an honors course. I love the approach, but I was not up to the task. It's completely different, and it requires you to really re-orient yourself. Doing that while getting a research program off the ground is hard. Doing that while also teaching a traditional freshman physics course from a different book is damn near impossible, because you're in two different mindsets (and the sections met back-to-back, so there was even less time to re-orient the mind). And doing it as a solo project, one that much of the rest of the department is merely tolerating rather than supporting, truly is impossible.
I would love to teach from M&I in the future, but under different circumstances.
In fairness to the WebAssign problems, the basic issue is that the publisher isn't supporting the book much, so the only problems available in WebAssign are the ones that the authors themselves prepared. They haven't assigned staff to put all of the book problems into WebAssign the way that publishers do for more widely-adopted books. If more schools adopt it, I think they'll put more problems into WebAssign.
I see that I *really* need to write that blog about "concepts" and engage this question.
My observation for you is that your evaluation of the course should not end with the final exam. Some of your students are physics majors: how will their preparation for bigger ideas like the Hamiltonian, and smaller ones like solving problems, be judged by their junior-mechanics instructor? More of your students are probably engineering majors: how will their preparation be judged in their first engineering mechanics class? The latter will have a block on a plane with a set of pulleys connecting the rope to a motor plus friction that depends on velocity. (My mechanics class had a problem like that too, only the pulley was rolling down a hill.)
I think you see where I am going with this. A course like physics 1 does not stand alone in the universe, with outcomes you measure and then are done. It lives in a curriculum where it links (seamlessly?) with other courses and either enhances them or hinders them.
The curriculum of M+I is different enough that it should show up as a phase transition - for good or bad - in the preparation of students moving into physics or engineering. I think you should track that as part of the effort of your faculty in deciding if it serves your purposes. You might not know for a year or two, but you will only know if you look at it systematically.
PS to Emmy -
The unhappy bunnies were made of cheese.
Did you incorporate vpython and computational stuff? How did that go?
Not terribly well, in large part because this was a very unusual population for the intro mechanics class-- only 5 of the 16 students in the class were engineering majors, with the rest being mostly bio/chem majors who should've been in the "Physics for Life Sciences" course instead.
This also makes it hard to try to correlate the scores from this class with scores in future classes-- the population I had was not the population this course is designed to be serving. I suppose you could try to match it to MCAT scores, but I don't think this class would do a terribly good job of preparing them for the MCAT.
I used M&I for one quarter in an honors course. I love the approach, but I was not up to the task. It's completely different, and it requires you to really re-orient yourself. Doing that while getting a research program off the ground is hard. Doing that while also teaching a traditional freshman physics course from a different book is damn near impossible, because you're in two different mindsets (and the sections met back-to-back, so there was even less time to re-orient the mind). And doing it as a solo project, one that much of the rest of the department is merely tolerating rather than supporting, truly is impossible.
Not only impossible, but insane. Particularly if you're pre-tenure.
The curriculum of M+I is different enough that it should show up as a phase transition - for good or bad - in the preparation of students moving into physics or engineering. I think you should track that as part of the effort of your faculty in deciding if it serves your purposes. You might not know for a year or two, but you will only know if you look at it systematically.
We're doing that. This is the second year of M&I in the general intro mechanics course, after a couple of years of M&I in the honors section. It's my first time teaching it due to accidents of scheduling.
I wouldn't care to speculate publicly about what effect, if any, this has had.
If the bulk of your students are future non-physicists (which they are, even at the geekiest, techiest schools), covering quantization is a waste of time. It steals away time that should be spent on the conservation laws anyways.
I'm quite glad you focused on those, they are truly what matter. Unfortunately engineers are not geared to thinking in that way. I remember taking a fluid dynamics class my last semester in school. My classmates were lost a lot when I asked something because they weren't used to either the mathematical demands or the use of conservation principles to analyze something. And the jargon switch is pretty confusing too. There was a special lecture about an exam problem where every single person who tried to use Bernoulli's principle and torque balance (i.e., static rotational equilibrium) got it wrong because they tried to plug things directly into equation instead of actually analyzing the situation. As the lecture progressed I asked something, thoroughly confusing the prof. As soon as I translated the question, he figured out what I didn't understand and cleared it up for us.