Why should I use peer instruction in my class?

Image: "Lecture Hall," uniinnsbruck, Flickr (CC)

[Update (June 16): Lead author Zdeslav Hrepic pointed me to a follow-up book chapter [PDF] where he and the study co-authors describe using tablet-PCs to counter the problems uncovered in their study. Thanks, Z.]

I’m sure we’ve all heard it from skeptical instructors: Why should I use peer instruction in my class? In response, we often cite Hake’s 6000-student study or the new UBC study by my colleagues Louis, Ellen and Carl. These are still pretty abstract, though: If you use interactive, learner-centered instruction, you can expect your students to better grasp of the concepts.

“Sure, but why?” the instructors ask. “Why does it work?”

I just read a paper that can help answer that question. I ran across it while following a discussion about the Khan Academy videos and whether or not they are good tools for learning. This paper by Hrepic, Zollman and Rebello (2007) asks students in an introductory physics course and physics experts (with M.Sc’s and Ph.D’s) to watch a 15 minute video of a renowned physics educator presenting a topic in physics.

The researchers do a series of pre- and post-tests and interviews with the students and experts to compare their understanding of the concepts covered (or not) in the video. There were some significant differences. A couple that stick in my head. (1) students recalled learning about concepts that were not presented in the video. (2) Only students who knew the correct answers on the pre-test were able to infer the concepts from the video (that is, the questions were not explicitly answered in the video.) The students who did not know the concept before were unable to make the inferences. Like I said, there are significant differences between what the instructor thinks a lecture covers and what the students think is covered.

The paper nicely gives us some suggestions to counter this problem.

And my thoughts about how to use peer instruction to do that.

Making inferences: Experts make more inferences than students. And only students who already know the concepts can infer them from the lecture. Therefore, instructors need to be cautious about relying on students to fill in the blanks.

Some of the best peer instruction questions are the conceptual questions where the answer is not simple recall. No traxoline here, please. Questions that rely on students making inferences are excellent for promoting discussion because it’s likely students will interpret the question differently, make different assumptions and come to different conclusions. <soapbox> All the more reason that students need to first answer clicker questions on their own so they’re prepared to share their inferences. </soapbox>

Prior knowledge: Students’ prior knowledge influences what they perceive and can “distort” their recollection of what the lecturer says. Therefore, it’s essential that the instructor has some idea of what the students already know (particularly their misconceptions) before presenting new material.

A few, introductory clicker questions will reveal the students’ prior knowledge. Sure, maybe these are simple recall questions that won’t generate a lot of discussion. But the students’ responses will inform the agile instructor who can tailor the instruction.

Continuous feedback about students’ understanding: The trail the instructor blazes through the concepts and the path the students follow often diverge during a lecture. The instructor should be continuously gathering and reacting to feedback from the students about their understanding so the instructor can shepherd the students back on track.

Observant instructors can gather critical feedback from the discussions that occur during peer instruction or the students answers on in-class worksheets like the Lecture-Tutorials popular in introductory “Astro 101” classes and other hybrids of the Washington Tutorials. Rather than waiting weeks until after the midterm or final exam to find out students totally missed Concept X, the instructor can discover it within minutes of introducing the topic. Minutes, not weeks! The agile instructor can immediately revisit the difficult concepts. Immediately, not weeks later or never!

I’m much more confident I can answer the skeptical instructor now. “Why should I use clickers in my classroom?” Because they give the students and you to ability to assess the current level of understanding of the concepts. Current, right now, before it’s too late and the house of cards you’re so carefully building come crashing down.

9 Replies to “Why should I use peer instruction in my class?”

  1. Nice post. ๐Ÿ™‚ Clicker questions and the “think-pair-share” method (as taught by the CAE) proved enormously useful to seeing what my AS101 students were and were not getting. I feel really naive about this now, but my method for determining if they were getting the material was to simply ask(!) Of course they said they understood, it was only when the test came around that I could see that wasn’t the case for all of them. I don’t think the students were lying, but not all of them were able to properly access their understanding. Clicker questions are a real help in this area. It also breaks up the lecture and keeps people engaged.

    1. Thanks, Carrie. Did I use the word “effective” when writing about peer instruction? If not here, I try to everywhere else I describe it. And by effective, I mean the “choreography” taught in the CAE workshops.

  2. I like your stand on having the students answer the clicker questions on their own before class. I have been using peer instruction in my 9th grade physical science class this past year and it’s gone well, but I had not thought about having the students think about some of the questions before class. I’ll have to try that! I recently started blogging and one of my first posts is about the low-tech clicker system I have had much success with in my class. Cost is probably not an issue at the college level, but it may be at the high school level.

  3. I have successfully implemented peer instruction in my 9th grade physical science class over the last year – the students enjoy the interaction with each other. I agree with your point that the teacher can immediately diagnose misconceptions and address them on the spot. I like your stand on having students think about and answer clicker questions on their own before coming to class. I haven’t tried that before – I’ll have to try it and see how it goes this fall… I recently posted on my blog about the low-tech student response system I use – not a completely new idea, but I think I have a pretty slick system. While funding for digital student response systems is probably not too much of an issue at the university level, it can be at the K-12 level.

    1. Thanks for the comment. I think it’s really important for the students to think on their own first so they’re prepared to have a meaningful conversation. And if we value that thinking, we have to give them sufficient time to do it. And let them know they have time to do it.

      How long is “sufficient”? Good question. Some instructors always give 1 minute or 2 minutes or some fixed time. That may be simple to implement but I don’t think it’s optimal. Some questions take less time and the students have to wait, losing their focus. Some questions take more time and they’re forced to commit to an answer before they’re ready.

      In our introductory astronomy courses, we follow the practice promoted by the Center for Astronomy Education at the University of Arizona. The instructor puts up the question (typically a PPT slide), turns to the screen and reads the question “student-slow” That is, you read every word like it’s the first you’ve seen the question. And then you answer it, deciding which answer is correct and which are not. You have to role-play (in your head) a bit, pretending you’re thinking like one of your reasonable students. Not the brainiac and not the meh-whatever student but the reasonable B-student. If you take that long to answer the question, that’s likely how long they take.

      Of course, it never hurts to check. We turn back to the class and ask, “Do you need more time?” Silence means they’re ready to vote. If you’ve created a welcoming culture in the classroom, students who are not ready will tell you, “NO! I need more time!”. So turn back to the screen, quickly go over your answer again, and get them to vote.

      That’s our operational definition of “sufficient time.”

      By the way, students might be reluctant, at first, to admit they need more time. So plant somebody. Talk to one of those brainiacs before class and ask them to yell out, “No! I need more time.” When you gladly give it to them, without any suggestion that they’re dumb or slowing down the class, the other students will see it’s okay to ask for time. After all, isn’t one of the goals of peer instruction to encourage students to think and then judge their confidence in their answers? Knowing whether or not you’re ready to answer is highly metacognitive!

      By the way, I followed the link to your blog and read about your low-cost coloured-cards. The laminated string-of-cards is ingenious! I’ll be sharing that with my colleagues.

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