Discover the Power of Peer Instruction for Intro E&M Classes

[ZapperZ]

I've been paying attention to this teaching methodology for a few years (even before I became an educator), and over the past couple of years, have started to incorporate parts of its technique into my classes. But this year, I've decided to go into it head on and going all in for my intro E&M class. I think it is because I'm finally comfortable with the "pre-lectures" that are available to the students and also the various conceptual questions that I can bring out to the students to gauge their understanding.

But still, I'm always finding new things to learn and new insights into this methodology. Even using Eric Mazur's guidelines, I find that I often do considerable tweaking because of the type of students that I get. I find that I have to go over a lot more conceptual issues with students who are not physical science/engineering majors, and often, these take up a larger portion of lecture time than I expected.

One of the things that we practice is having students work in groups on the whiteboard on a particular problem. My class is in one of the "special classrooms" in which there are whiteboards all around the room. This enables students to get up and work on the whiteboards and discuss among themselves on how to arrive at the answer. I walk around merely as a guide if they need help ("Are you sure that is the correct units?", "Why did you choose to solve it this way, and not that way?"). We also have clickers for each students to use when we do a poll on conceptual questions. I follow rather closely to what Mazur has suggested in dealing with the poll results.

So, is there anyone else adopting this technique? Do you have any special insight into this methodology? Do you have neat conceptual questions in E&M that you like to pass along? I'd also like to find out if this technique is being used outside of the US.

Zz.

 

[berkeman]

I'm curious -- how often do you find yourself having to correct students as they are working? How often do they head off into the weeds as a group, and need to be corrected to get them back on track?

The only teaching I do currently is in Citizen Emergency Preparedness, and at the end of a couple-week-long (part-time) set of classes, we have a practical drill at a local fire station. The current Fire Department that I help teach under has a philosophy for the final drill exercises that the students should be demonstrating the skills they have learned, with minimum input from the instructors at this point. It seems to work for most of the drill stations, but I've found it not to work well for the Medical stations.

The problem is that the students are not medical professionals, so the medical skills we teach them in the classes are not very familiar to them. They don't practice them every day like we do, so when they try to demonstrate some of the medical skills without much preparation/review from us in the drill, they generally make lots of mistakes that need to be corrected. IMO, that hurts their "muscle memory" for doing the skill, because they've started off doing it wrong, and correcting that interferes with the continued formation of "muscle memory". It also confuses the other students watching the drill, because they often start thinking to themselves, "Oh, is that how we're supposed to do it?" A few moments of confusion at the beginning of each part of the Medical drill exercises is bad for the students' memory and skills, IMO.

So for the Medical part of the drill exercises, I always do a quick review of the skill before having the students demonstrate it to me. It keeps their thinking process clearer, and helps them keep building good "muscle memory" of the skill without unfortunate distractions.

I know that this doesn't translate directly to your classroom environment, but I think that's one of the concerns folks may have with peer instruction -- how long and how often do you let initial errors go on? You can't be with every group at once when they start talking through a problem, but maybe from a central location in the room you can see which group(s) are quickly heading off into the weeds and do some sort of correction?

 

[Andy Resnick]

So, is there anyone else adopting this technique? Do you have any special insight into this methodology? Do you have neat conceptual questions in E&M that you like to pass along? I'd also like to find out if this technique is being used outside of the US.

Zz.

A few of us here (US 4-year university) do peer instruction in the intro classes (physics I, II, and astronomy). Note, there are many 'flavors' of peer instruction, but as long as you are focusing on the intent rather than the gadgets, you should see improvement. I do some peer instruction in my intro classes and constantly struggle with a basic tradeoff: how to cover the amount of required material versus allowing the students time to work through a single problem. I haven't yet found a good solution.

 

[berkeman]

because they've started off doing it wrong, and correcting that interferes with the continued formation of "muscle memory"

I've thought more about this, and I think I see what the difference is now between the training I am talking about and the physics/math instruction @ZapperZ and @Andy Resnick are doing. In EMS, we have set procedures and protocols, and we need to learn to be able to repeat those actions and decisions very precisely every time. "Muscle memory" is truly very important, and having confusing things happen during training is generally a bad thing.

But in science, each problem presents a unique mix of the previous things you've learned, and you have to get good at adapting and figuring out what equations and techniques apply to a particular problem you are presented with. It's okay to spend a minute or two trying out things that are actually not helpful, because that guides you to move more to the other techniques you have that do actually apply. It's actually a good skill to learn and practice, so maybe Peer Instruction has that as a strength, not a weakness.

Of course you still have to watch out for students who state things that are clearly wrong, like "KE is conserved in inelastic collisions" or similar. But that probably happens pretty rarely, and could even turn into a teachable moment helping the student to understand why it is wrong.

 

[Dr. Courtney]

My experience is that one needs to be able to count on a certain level of preparation for peer instruction to be effective. I could usually count on this at the Air Force Academy, and my wife could at West Point, but the approach was not really viable for class time at the state schools where we've taught. However, at those schools, it could be very productive during office hours when working with smaller numbers of prepared students.

We borrowed the approach of the West Point Department of Physics and Nuclear Engineering (PANE). They described teaching as a three part process:

Model - explain the principle and demonstrate the problem solving techniques (be the sage on the stage).

Coach - back off and let the students go to the board and do it. Peer instruction allows them to coach each other, and only steps in for bigger time wasters, misconceptions and rabbit trails. (be the guide on the side).

Fade - As student mastery (and ability to help each other) grows on a given topic, the instructor's contributions asymptotically approach zero.

Better student preparation and the presence of student leaders tends to allow one to move from model to coach and from coach to fade more quickly.

 

[ZapperZ]

I do some peer instruction in my intro classes and constantly struggle with a basic tradeoff: how to cover the amount of required material versus allowing the students time to work through a single problem. I haven't yet found a good solution.

I am SO glad you said that, because I have the same issue. It is the first class where I'm 100% in for peer-instruction, and I am having a bit of an issue in juggling how much time I allocate to introducing the material, and how much time I give for students to work on a problem. In fact, in my first class this semester, I ran long, and ended up not being able to do any in-class problems.

The problem here is that, while the material being presented in the pre-lectures are complete and adequate, I find that often, they do not put enough emphasis on the salient, important points. When I teach in class, I tend to emphasize and repeat stuff that I think that students need to know. This way, they may realize what the punch lines are in whatever it is that I'm introducing. So it is more of an issue with me "trusting" that the students got the important points from the pre-lectures before the come into my class.

In any case, so far, I think things are going well, better than I expected. I think that almost 3/4 of the students in my intro E&M class already had similar peer-instruction classes before this, and they took to the group-work like fish to water.

Zz.

 

[Andy Resnick]

I am SO glad you said that, because I have the same issue. It is the first class where I'm 100% in for peer-instruction, and I am having a bit of an issue in juggling how much time I allocate to introducing the material, and how much time I give for students to work on a problem. In fact, in my first class this semester, I ran long, and ended up not being able to do any in-class problems.

Glad to hear things are going well- I agree that once students have been exposed to peer instruction, they are much more likely to 'buy in' to the system. I also agree that clearly stating what the 'salient, important points' are to students is critical.

My intro class starts tomorrow- I'm leading with a 'scotch tap electrometer' to demonstrate two types of non-contact interaction (attractive and repulsive), with the goal of motivating a discussion about charge and field. Let's hope the humidity is low enough...