The Importance of Shaking Things Up

That recent study on active learning continues to generate some press, including a new interview with Carl Wieman about why traditional lectures are problematic. Wieman is pretty blunt about his opinions on the subject, which will come as no surprise to people in the AMO physics community...

Anyway, while most of the rest of the academic nation is into final exams and even graduation parties, we still have two more weeks of class after this one, and we're giving an exam tonight in my intro E&M class. Which means I'm still spending a lot of time thinking about this stuff. Some related material also came up in this week's Uncertain Dots, when Rhett and I talked about what we want from students coming into intro college physics. In particular, I'm thinking about the bit where Rhett says he'd prefer students who haven't taken any physics at all, while I would like them to at least have a rough idea of what some of the basic concepts are.

As I tried to say in the hangout, but kind of bungled, I think this is largely due to a difference in the populations we see-- I'm at a snooty private liberal arts college in the Northeast, while Rhett is at a public university in the South. The vast majority of the kids I see in class come from privileged backgrounds, and the high school physics classes they've had are mostly pretty good. So some of the bigger problems that come from half-understanding previous material don't come up that often for us. If I were seeing more kids from schools with subpar physics classes, I might also prefer that they not have physics at all.

Of course, on the flip side, it's important to shake up even the kids with a decent background in physics, because as I've said before in talking about our intro curriculum-- cited in Rhett's Matter and Interactions evangelism post-- one of the things I like about it is that the approach is just different enough to keep students with a good background on their toes. The traditional curriculum-- Halliday and Resnick is the canonical book-- looks very much like a high school physics class for the first several weeks, with the occasional addition of some vector symbols. When we taught on that sort of curriculum, I used to watch students with good backgrounds slowly degrade as the class went on. Once they realized they could mostly fall back on what they'd had in high school, they would stop paying attention in class, or stop coming altogether. And when we hit them with genuinely new stuff six or seven weeks in, their study habits had fallen apart to such a degree that they really couldn't handle it.

Matter and Interactions shakes things up just enough to keep them engaged. The ideas are sort of familiar, but there's enough of a difference in the language used to talk about them, and the ordering of topics, that students have to pay attention in class and on the homework. Which means that they don't go to pieces in exactly the same way later in the course. Those students end up having a better experience as a result, and they're the kind of B+/A- crew that can turn out to be really good if you can get them engaged, but turn into B/B- students when they're bored.

I forget who sent me the original link, now, but I recently got pointed to a different study from Carl Wieman "The Surprising Impact of Seat Location on Student Performance" (paywalled, but if you Google the title, you can find the PDF pretty easily). This was a study of a large non-majors course, where they randomly assigned students to seats, and tracked their subsequent performance. They found that students initially placed in the back of the large lecture hall did worse in the class, even after they were shifted to seats up front halfway through. I suspect the mechanism here is similar to the traditional-curriculum problem I mentioned-- it's harder to be deeply engaged from the back of a big room, and as a result students' study habits degrade over the early part of the term, to a point where they can't really recover later on. It'd be interesting to see a follow-up study where they switched seats front to back more frequently, to see what the decay constant is for student focus. If I'm ever in a position where I'm teaching in a large lecture hall, I'll definitely try to move people around a bit, for just this reason.

This is also probably a piece of the "active learning" effect-- if you force students to do something during class other than just sit and stare, they're less likely to tune out completely, and more likely to maintain good habits through a longer stretch of the course. It's also probably worthwhile to switch up the groups for "active learning" discussions on a regular basis, though I'm not very consistent about doing that for a couple of reasons, only one of which is basic laziness. There are limits, of course-- the active methods they used weren't enough to overcome the seat location problem-- but I think just shaking up the normal routine is probably a part of the story.

So, anyway, those are some of the things I'm thinking about physics education right at the moment, as the term slooooowly winds down.


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Re: Wieman

Think of how much scientific progress might have been made if he had stayed in AMO....

Every way of teaching a subject tends cause it's own set of problem. For instance, in Sweden we have a standard national curriculum, and teach "Halliday and Resnick"-light at the upper secondrary level. University physics students then usually begin with "Kleppner & Kolenkow" or similar subject book in mechanics for their first physics course. Instead of the "bored" good student problem, students feel that the transition often is a very big step.

By Fredrik Janson (not verified) on 22 May 2014 #permalink

Do you switch up lab partners? I've found that even ones with a dunce partner (e.g. a guy who knows less than nothing but convinces a female partner that he knows the right way to do something) are stuck with social glue. That said, my physics classes come with ready-made teams because there are groups who know each other from math or chemistry classes. My gen ed classes do NOT want to interact at all!

On seat location:
My back row isn't that far away and I have ways of getting back there, but the self-selection effect is real. Odds that an F will sit in the back row NEAR THE DOOR are real high. However, I also have some very good students sit back there because they are shy/quiet. I've never tried to assign seats.

On HS:
I agree on teaching concepts in HS.

Otherwise, I share Rhett's opinion and believe you are seeing a selection effect subject to the answer one question: Can those kids who had physics before (and then fall behind) solve problems "correctly", by starting at the beginning and doing algebra up to the last computing step, or do they equation grab from memory? Because almost none of my students have done word problems in their math classes, and because chemistry is taught in a near equation-free zone that emphasizes dimensional analysis with only linear relations, some who learned those bad habits are in for big trouble.

One of the worst things I have seen, repeatedly, are students who write "ma" as if it was a force on a free-body diagram and write everything as net F = 0. Someone is teaching them that, somewhere.

Another bad habit is writing down lots of rounded intermediate numbers because (a) someone did that all the time in (math?) classes where the numbers were single digit integers and (b) they do not know how to use their calculator any other way.

By CCPhysicist (not verified) on 25 May 2014 #permalink

I've done lots of different things with the partners issue. I've assigned groups, I've gone with self-selected groups, I've randomly shifted people between groups, etc. Changing up groups is unpopular as a general rule. It's also difficult to avoid creating some problems-- splitting up a group that was working and putting a clueful but not confident woman with a guy who has tons of confidence and impeccably wrong intuition, for example.

I've also seen the "social glue" thing in action, in terms when I assigned group lab reports-- part of the grade for those was a "peer evaluation," where I asked students to rate the performance of their lab partners (they were in groups of three) by distributing "points" among them. With very few exceptions, students would distribute the points equally between their partners, even in groups where one member was clearly incompetent. It was kind of maddening.

I need to get a copy of Matter and Interactions to review, but there is one question that puzzles me concerning the table of contents as well as your remarks in Uncertain Dots 13: what labs do you do in the 2nd course? We have limited (but not zero) options outside of circuits.

Of course, one option would be to run the lab as a free-standing circuits-only class, but that isn't really satisfactory either.

By CCPhysicist (not verified) on 25 May 2014 #permalink

A lot of the labs we do in the introductory E&M class are more like discovery activities than labs. This term we did:

A torsion pendulum experiment to check Coulomb's Law

A charging-by-induction lab with electroscopes

VPython calculation of the field of extended objects

Measuring the magnetic field of the Earth with a tangent galvanometer

Circuits/ Kirchoff's Laws

RC time constant of a capacitor

This week we'll be doing a measurement of e/m with electrons in a magnetic field

Next week will be Faraday's Law.

Of those, the only ones that I've run like "real" labs are the Coulomb balance, tangent galvo, and (tomorrow, anyway) the e/m. The rest are kind of terrible as traditional labs-- you either don't measure anything quantitative, or just confirm a formula from class-- so I mostly folded them in with lecture as motivation for/ illustration of stuff we were talking about anyway.

Thanks. I need to think about using VPython for that kind of problem (it was described by either you or Rhett recently). I can't assume the appropriate computing devices in class, but they have plenty in lab. My only problem is that I can only be sure it will work if I am teaching the lab.

I also liked your twist on the regular Kirchhoff-type lab. "Measure everything and sort it out."

BTW, I take off points if the group blows a fuse, and I always have some sort of "can you wire it up" practical on the lab exam, mainly because that is something I know they will do in their engineering circuit lab.

By CCPhysicist (not verified) on 26 May 2014 #permalink