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