Stable and unstable lectures
Posted by Arjendu on April 17, 2008
As I’ve said a few times before in this blog, I prefer to let students read the text to get a preliminary take on physics content on their own, generate questions and confusions on which I focus during ‘lecture’, and then check their comprehension of these principles by working together on applying them via problem-solving — and doing this in my presence so I can help them work out what they do and don’t know.
I see this as directing the class’s and my energy at the biggest road-blocks to mastery. The traditional method of (i) presenting a lecture in class, (ii) asking students to respond to the lecture presentation with questions, and then (iii) go home to work on problems, seems to me to be quite inefficient.
This, I argue, is because (i) the lecture is usually being spent telling people what might be relatively simple, or missing the troublesome issues. This is because no matter how hard I’ve tried to do figure out what’s easy and what’s hard, every year and every class turns out to have different blind spots and troublesome issues (apart from the blindingly obvious things like, say, Newton’s Third Law for intro mechanics students). (ii) The students haven’t had time to think about a presented point when I ask for questions, so I am not really clearing up confusions for anyone but the fastest thinkers or the best prepared students. And (iii) when they are trying to solve problems, and true confusion pops up, they are on their own.
The way I choose do things means that I always walk into a classroom feeling slightly unstable. That is, I don’t quite know what I will be talking about and never know how the time will be spent. I figure this is a fair trade-off for the gains I’ve noted above, and on a good day, I feel like improvisation is my strength ( well-prepared lecture notes, while I can do those, certainly isn’t a strength, so something’s gotta be!).
But there is another downside that I periodically forget about: What’s happened at the end of a long discussion about ‘problems’ and ‘confusing issues’ is that unless these have been completely and totally nailed by the discussion, we’ve spent the whole class out of the students’ comfort zones, and they’ve also felt unstable through out. They haven’t had the opportunity to sit back and listen to someone tell them something they sort of know already, or find easy to understand, and as a result, their mood can be somewhat grumpy and discouraged.
I haven’t yet figured out how to deal with this, to be honest. I am fully aware that this sort of discomfort with the material would’ve been there in any case, just hidden from public view in the standard chalk and talk class and I should probably feel pleased that I am getting to confront it. But I can’t help wanting to change it some. Usually I resort to short lectures for a few classes after I hit one of these particularly discombobulating classes — I find that it reassures the students and me, stabilizes the dynamics, as it were — and then I can drift slowly back to my preferred style again. But that seems inconsistent to me, and I am going to try to come up with other ways of getting this stability this term. Any thoughts, advice, pointers from readers?