TLL Library

"Active Learning, Part II, Suggestions for Using Active Learning
Techniques in the Classroom,"
Vol. XII, No. 3, January/February 2000

Lori Breslow

I was having dinner with a group of my students last week when the conversation turned to the freshman year. The students, most of whom are juniors and seniors, were reminiscing about how they had managed to survive that first year. They talked about the steady stream of problem sets, the course material that seemed at times impenetrable, and the routine of cramming for test after test. When I asked them what they thought they had learned in that year, one of them, I’ll call him David, said, "The thing the freshman year taught me best was how to be a passive learner." David’s comment was a conversation stopper; I gathered most of the group agreed with him.

The good news is that with Alex and Brit d’Arbeloff’s gift to support innovation in the freshman year, MIT faculty and students will be working together to create initiatives that will offer alternatives to the way freshman subjects are currently taught. This will open up possibilities for students who are not thriving under the current curriculum, and for faculty who are frustrated because they cannot "reach" their students. "The only problem is," warned a colleague of mine from a university with a freshman-year curriculum that extensively utilizes active learning, "once students get into their upper-level courses, they complain like crazy if the class uses the old sit-and-listen-to-the-lectures technique." So we need to get ready!

In the last "Teach Talk," I described a body of research that shows that active learning methods work: In classes that use active learning, students learn more, retain more, and have a more positive attitude toward the subject matter of the course. In this "Teach Talk," I want to describe a few of the specific techniques that are commonly used when instructors move away from the strict lecture format. (To remind readers, I am using the phrase "active learning" to refer to a range of techniques that get students actually engaged in the classroom. The richest definition I have found comes from Richard Hake, an emeritus professor of physics at Indiana University, who writes that active learning is "designed in part to promote conceptual understanding through interactive engagement of students in heads-on (always) and hands-on (usually) activities which yield immediate feedback through discussion with peers and/or instructors." (p. 65) ["Interactive-engagement versus traditional methods: A six-thousand-student survey of mechanics test data for introductory physics courses," American Journal of Physics, 66, 64-74, 1998.])

Active learning can be as simple as engaging students in Q&A during class, or it can be as involved as having them work on semester-long, team-based design projects. Here I would like to focus on three activities that have been used successfully in MIT classrooms: peer instruction, "the muddiest point in the lecture," and in-class group work on problems. An accompanying sidebar provides a more complete list of active learning techniques.

Peer Instruction: Active Learning in Large Lectures

Professor Hale Bradt is explaining magnetic energy dissipation to his Physics II (8.02) class. Referring to a diagram of a LR circuit he has on an overhead, at about 15 minutes into his lecture, Bradt stops and asks the students this question: "At Time 0, the energy dissipated in R equals the energy stored in L. True or False." The students think about the answer for a few minutes, then raise their hands when Bradt asks, "How many think true? How many think false?" Next he asks the students to talk to each other about the problem. A low buzz engulfs the classroom. After a few minutes, Bradt asks for a show of hands again.

This technique, called peer instruction, was pioneered and popularized by Eric Mazur, a physics professor at Harvard. Mazur was discouraged about how little his students were learning when he used conventional lectures. As he writes in his book, Peer Instruction: A User’s Manual, "Analysis of my students’ understanding of Newtonian mechanics made it clear: They were not learning what I wanted them to learn. I could have blamed the students for this . . . . [Instead] I decided to change my teaching style and discovered that I could do much better in helping my students learn physics." (p. xiii) The "change" Mazur refers to was to get his students actually working during the lecture itself with the material he was presenting.

Peer instruction works this way: Every 15-20 minutes the instructor stops lecturing and asks the students a question about the concepts he or she has been explaining. These questions, which are either true/false or multiple choice, require the students to do very little, if any, calculation. (For an example of a concept question drawn from 8.02 taught by Professor John Belcher, click here.) Students work the problem on their own for several minutes. Then they are asked to give an answer.

(While Professor Bradt has students raise their hands, other lecturers feel more comfortable giving students a way to hide their answers from one another, thereby protecting them from having to publicly commit to the wrong answer. Professor Belcher gives his students flashcards with numbers on them for this purpose. The rule is no one may turn around and look at the card anyone else is holding up. There is also a more technically sophisticated electronic system on the market, called Class Talk, which allows students to use a keypad to record their answers, but it is not available at MIT.)

After the students work on the problem individually, they are asked to talk about it with one or two of their classmates. Then they vote again. Mazur reports that the number of right answers almost always goes up after the students discuss the problem. (Mazur also asks students to report how confident they are about their answers; confidence levels also go up appreciably after discussion.)

There are at least two advantages to peer instruction. First, immediately after students hear the instructor explain a concept, they can work with it themselves. Second, the instructor can get instantaneous feedback on how he or she is getting the material across. In fact, if most of the class answers the question correctly on the first round, the instructor can decide to move on to the next topic. Or, if there still seems to be widespread confusion even after students have discussed the question with one another, the instructor can spend more time on the topic.

This technique can be used in smaller classes, too, of course. Course 16 (Aero/Astro) Professor Steven Hall uses it in Unified (16.010). He asks students to work individually on a problem. Following that, students team up in groups of two, and each person explains his or her answer to the other. The team then synthesizes the best possible answer, and either partner may be asked to brief the solution before the class. A typical 50-minute lecture will contain three main ideas &endash; 10 minutes of lecture on each with a concept test in between.

I read all of Professor Bradt’s evaluations the semester he began using peer instruction. Almost every one of his students was enthusiastic about the concept tests because they gave them a break from the lecture, and because they helped them gauge their own understanding of the material. A few students (no more than a dozen) felt the concept tests were a waste of time or resented having to do something during the lecture other than listen and take notes.

The thing that worries almost every instructor about peer instruction is the loss of time: If students are spending time talking about concept A, that’s time taken away from the instructor covering concept B. There is no getting around that. Professors Bradt, Belcher, and Hall estimate they cover between 10% and 15% less material because they use peer instruction. They also believe that is a small price to pay for an increase in comprehension. As Professor Bradt explains, "I don't feel I lose anything because I know the question is forcing them to think and get the basics down. Giving them another example is just not as productive. I only spend about five minutes on one of these concept questions &endash; so maybe 10% less material covered. But no loss of concepts &endash; just loss of more examples."

"The Muddiest Point in the Lecture"

In 1989 Frederick Mosteller’s article, "The ‘Muddiest Point in the Lecture’ as a Feedback Device," appeared in the journal On Teaching and Learning. Mosteller, a statistics professor at Harvard, advocated asking students in the last three or four minutes of every class three questions:

"(1) What was the most important point in the lecture?

(2) What was the muddiest point?

(3) What would you like to hear more about?" (p. 10). "This simple idea attracted me," writes Mosteller, "because it might feed into this course given now and give immediate benefit to this teacher and these students without the need to wait for next year." (p. 11).

The "muddiest point" has been used regularly in Aero/Astro’s Unified to acclaim by both faculty (five faculty regularly teach the subject) and students. The instructor distributes 3x5 index cards, and only asks students to identify the muddiest point. The students can sign their names or not to the cards. After class, the instructor sorts the cards into piles according to the unclear points identified or the questions asked. He can then do several things: talk about the question in the next class; send students an e-mail addressing the issue; make up a handout to give out in the next class period. Sometimes there can be just a handful of students who are confused about a particular point; a TA may be able to help them. And sometimes instructors who use this method report students hand in cards that say, "Everything was perfectly clear!"

Again, there are multiple benefits of the "muddiest point." It allows students to take five minutes at the end of class to reflect on what they have learned; it permits students to ask questions anonymously; it gives the instructor instant feedback; and it permits misconceptions to be cleared up within a class period. This is especially important in teaching the kind of technical material that is the bulwark of MIT classes, since concepts so often build upon one another. According to Professor Ian Waitz, another Unified faculty member and the chair of Aero/Astro’s Teaching Methods Team, "The ‘muddiest point’ has been one of the most successful &endash; if not the most successful &endash; of all the active learning techniques we have implemented. It’s an invaluable form of feedback both for the faculty and the students."

In-Class Group Work

Ideally, recitations are an opportunity for students and instructors to work together on material covered in the lecture that may still be troubling or confusing. Too often, they turn out to be lectures themselves with the recitation instructor working problem after problem on the board. But, again, the findings of recent educational research tell us that learning occurs most successfully when the learner is actively engaged with the material. In other words, the recitation instructor may be learning a lot, but it is not clear that the students, sitting passively in class watching problems worked for them, are getting very much out of it!

An alternative is to put students into small groups (two to four) and have them work on problems together. There are several factors to consider when using this approach, and several variations on how it can be implemented. Here are some suggestions:

Who forms the groups? You can put the students in the groups or ask them to form groups themselves. If you opt for self-selection, make sure every student is a member of a group. Some students find it difficult to work with others; while you can acknowledge that group work isn’t for everyone under every circumstance, you should explain this will be the norm for the class. Gently encourage students who don’t naturally put themselves into a group to do so.

Should the same students work together in each class? There are advantages to forming permanent groups that have to do with teaching students team dynamics. Given that this is usually not an objective of in-class group work, students can form and re-form groups at each class session.

How much time should be devoted to group work? Some instructors spend the first 10-15 minutes allowing students to work on a problem; then they use the rest of the time in recitation to work through that problem and others with the class. Other instructors devote all of the recitation to group work. I believe either format can be effective depending on your objectives. In any case, it is best to spend at least the first five minutes of the period orienting the students to the topic at hand, and the last five minutes summarizing the work that was done that day.

What role should the instructor play? After the team has been working together for at least a short period of time, you can move around the class, making yourself available to the students. At first, having the instructor "eavesdrop" may make the students self-conscious. But when it is clear that you are a resource for the students, you should be able to move among the groups naturally. You can also stop the group work and reconvene the class as a whole if you see a common problem cropping up for most of the students.

What happens if one or two students in the group get the answer much more quickly than others, or if one group finishes much sooner than the rest? I believe the group should be encouraged to work as a whole: that is, more capable students should be asked to help their teammates understand the material. If students seem reluctant to do that (and some will), explain that teaching something to another person is the best way to reinforce your own learning! One instructor keeps several harder problems in his "back pocket" for students or groups who finish the assigned problems quickly.

Should students then be chosen to work the problems on the board? In the recitations that I’ve observed, asking students to work whole problems on the board has not been particularly effective. Students seem to have a hard time re-creating the steps they went through to solve the problem, or they are unfamiliar with speaking in front of a group at a blackboard.

A be recitations that I’ve observed, asking students to work whole problems on the board has not been particularly effective. Students seem to have a hard time re-creating the steps they went through to solve the problem, or they are unfamiliar with speaking in front of a group at a blackboard.

A better technique is to give different students specific questions to answer. You may want to develop the entire solution to the problem step by step. Or, you may want only to discuss the first step in solving the problem, the key idea, or the places where students are likely to have difficulty. This kind of focused discussion keeps the class much more on target, and makes the best use of the available time.

When during the semester should this technique be implemented? The sooner the better. If you intend to use in-class group work, tell the students that this will be the way the class will be run on the first day. (That allows students who may be reluctant to participate in groups to switch sections.) One recitation instructor gave out a sheet the first day of class that outlined the method he intended to use.

Each of the methods described here will require some experimentation in order to work most effectively in an individual subject, with specific material and particular course objectives. Active learning also requires a shift in the relationship between the instructor and the students. As people in education circles say, the instructor has to change from being a "sage on stage" to a "guide on the side." I prefer to think that the instructor can widen his or her repertoire of pedagogical tools to incorporate both. There is much satisfaction in doing so.