At the star-studded Harvard Initiative on Learning and Teaching (HILT) event earlier this month, where professors gathered to discuss innovative strategies for learning and teaching, Harvard’s  professor Eric Mazur gave a talk on the benefits of practicing peer instruction in class, rather than the traditional lecture. The idea is getting traction. Here’s more about the practice.
By Emily Hanford, American RadioWorks

It’s a typical scene: a few minutes before 11:00 on a Tuesday morning and about 200 sleepy-looking college students are taking their seats in a large lecture hall – chatting, laughing, calling out to each other across the aisles. Class begins with a big “shhhh” from the instructor.

This is an introductory chemistry class at a state university. For the next hour and 15 minutes, the instructor will lecture and the students will take notes. By the end of class, the three large blackboards at the front of the room will be covered with equations and formulas.

Students in this class say the instructor is one of the best lecturers in the department. Still, it’s not easy to sit through a long lecture, says student Jimmy Orr. “When it’s for an hour you kind of zone out for a little bit,” he says.

Student Marly Dainton says she doesn’t think she’ll remember much from this class.

“I’m going to put it to short-term memory,” she says. Once she takes the exam, Dainton expectsshe’ll forget a lot of what she learned.

One of the Oldest Teaching Methods

Research conducted over the past few decades shows it’s impossible for students to take in and process all the information presented during a typical lecture, and yet this is one of the primary ways college students are taught, particularly in introductory courses.

It’s a tradition going back thousands of years.

Physics professor Joe Redish at the University of Maryland.

“Before printing, it was very difficult to create books, and so someone would read the books to everybody who would copy them down,” says Joe Redish, a professor of physics at the University of Maryland. He points out that the word “lecture” comes from the Latin word meaning “to read.”

Redish is trying to change the way college students are taught. He says lecturing has never been an effective teaching method, and now that information is so easily accessible, lecturing is a waste of time.

“With modern technology, if all there is is lectures, we don’t need faculty to do it,” Redish says. “Get ’em to do it once, put it on the web, and fire the faculty.”

Redish has been teaching at the University of Maryland since 1970. When he started, he lectured because that’s the way he had been taught. But after a few years in the classroom, Redish was meeting with one of his mentors, a famous physicist named Lewis Elton who had begun doing research on education.

“He asked me, ‘How’s your teaching?'”

Redish told him it was going well, but that he seemed to be most effective with the students “who do really well and are motivated” about physics.

Elton looked at Redish, smiled, and said, “They’re the ones who don’t really need you.”

“That was like an arrow to the breast!” says Redish.

He knew that Elton was right. Most of the students in his lecture classes were not motivated to learn physics, and they didn’t seem to be learning much. Redish thought back on his own experience as a college student and realized that he didn’t learn much in lecture classes either.

“When I had a question, I would find the TA,” he says. “He would explain stuff to me. I would find other students. I learned how to learn physics on my own.”

How People Learn

Redish wanted to reach the students who weren’t teaching themselves. So he began trying to better understand how people learn.

This was the 1970s and 80s, a time when cognitive scientists were making big breakthroughs in their understanding of how the human brain processes and retains information. At the same time, a small and growing group of physicists was becoming interested in the questions that kept Redish up at night: What do students learn in a traditional lecture-based physics class, and are there ways to teach them better?

Cognitive scientists determined that people’s short-term memory is very limited – it can only process so much at once. A lot of the information presented in a typical lecture comes at students too fast and is quickly forgotten.

Physics education researchers, among whom Redish is now a leader, determined that the traditional lecture-based physics course where students sit and passively absorb information is not an effective way for students to learn. A lot of students can repeat the laws of physics and even solve complex problems, but many are doing it through rote memorization. Most students who complete a standard physics class never understand what the laws of physics mean, or how to apply them to real-world situations. (Read more about what physicists learned.)

Educating Everyone

It may seem obvious that lecturing isn’t the best method to get students thinking and learning. Project-based learning and other interactive approaches have been popular in elementary and secondary schools for a long time, and of course the discussion-based seminar is an age-old approach. But lecturing is still the dominant teaching method in large classes at the college level, and also at many high schools – especially in the sciences. Experts say different approaches to teaching large classes can help more students learn, and help them learn better.

“We want to have a class where everyone can be successful because we need everyone to be successful,” says Brian Lukoff, an education researcher at Harvard who is studying ways to more effectively teach large classes.

“We need to educate a population to compete in this global marketplace,” says Lukoff. We can’t do that by relying on a few motivated people to teach themselves. “We need a much larger swath of [the] population to be able to think critically and problem-solve.”

Lukoff works with Harvard physicist Eric Mazur, one of the pioneers in developing a new way to teach large classes. Mazur calls his approach “peer instruction.”

Discovering a New Way to Teach

Like Redish at the University of Maryland, Mazur began his teaching career by giving lectures. But in the early 1990s Mazur read about the research being done by Redish and other physicists interested in education. Mazur realized that even many of his Harvard students were getting through class by memorizing information but not really understanding the fundamental concepts of physics.

Harvard physics professor Eric Mazur preparing to teach class.

One day, after he discovered this, Mazur decided to spend a big chunk of class time reviewing a fundamental concept. Half his students had gotten a question about this concept wrong on a recent test. So Mazur gave what he thought was a thorough and thoughtful explanation of the concept. He went slowly, putting all kinds of helpful diagrams up on the board.

“I thought I’d nailed it,” he says. “I thought it was the best explanation one could possibly give of this question.”

Mazur triumphantly turned around. “Any questions?” he asked. The students just stared at him.

“Nobody raised their hand and said, well but what if this and what if that, simply because they were so confused they couldn’t,” he says. “I didn’t know what to do. But I knew one thing. I knew that 50 percent of the students had given the right answer.”

So for reasons he can’t remember, Mazur told the students to discuss the question with each other.

“And something happened in my classroom which I had never seen before,” he says. “The entire classroom erupted in chaos. They were dying to explain it to one another and to talk about it.”

Mazur says after just a few minutes of talking to each other, most of the students seemed to have a much better understanding of the concept he’d been trying to teach.

“The 50 percent who had the right answer effectively convinced the other 50 percent,” he says.

Here’s what Mazur has figured out about what goes on when the students talk with each other during peer instruction:

“Imagine two students sitting next to one another, Mary and John. Mary has the right answer because she understands it. John does not. Mary’s more likely, on average, to convince John than the other way around because she has the right reasoning.”

But here’s the irony. “Mary is more likely to convince John than professor Mazur in front of the class,” Mazur says.

“She’s only recently learned it and still has some feeling for the conceptual difficulties that she has whereas professor Mazur learned [the idea] such a long time ago that he can no longer understand why somebody has difficulty grasping it.”

That’s the irony of becoming an expert in your field, Mazur says. “It becomes not easier to teach, it becomes harder to teach because you’re unaware of the conceptual difficulties of a beginning learner.”

Peer Instruction

Mazur now teaches all of his classes using a “peer-instruction” approach. Rather than teaching by telling, he teaches by questioning. Mazur says it’s a particularly effective way to teach large classes.

Here’s how he does it: Before each class, students are assigned reading in the textbook. Pretty standard for a lecture class, but if you talk to college students you’ll find that many of them don’t bother with the reading ahead of time. They come to class to figure out what information the professor thinks is important, then they go to the textbook to read up on what they didn’t understand.

“In my approach I’ve inverted that,” says Mazur.

He expects students to familiarize themselves with the information beforehand so that class time can be spent helping them understand what the information means.

Eric Mazur teaching his class at Harvard.

To make sure his students are prepared, Mazur has set up a web-based monitoring system where everyone has to submit answers to questions about the reading prior to coming to class. The last question asks students to tell Mazur what confused them. He uses their answers to prepare a set of multiple-choice questions he uses during class.

Mazur begins class by giving a brief explanation of a concept he wants students to understand. Then he asks one of the multiple-choice questions. Students get a minute to think about the question on their own and then answer it using a mobile device that sends their answers to Mazur’s laptop.

Next, he asks the students to turn to the person sitting next to them and talk about the question. The class typically erupts in a cacophony of voices, as it did that first time he told students to talk to each other because he couldn’t figure out what else to do.

Once the students have discussed the question for a few minutes, Mazur instructs them to answer the question again.

You can see a video of Mazur’s peer instruction approach in action here:

Then the process repeats with a new question.

What Mazur has found over nearly 20 years of using peer instruction is that many more students choose the right answer after they have talked with their peers. And it’s not because they’re blindly following their neighbor’s lead. By the end of the semester, students have a deeper understanding of the fundamental concepts of physics than they did when Mazur was just lecturing. Students end up understanding nearly three times as much now, measured by a widely-used conceptual test.

In addition to having a deeper grasp of concepts, students in Mazur’s classes are better at solving conventional physics problems, despite the fact that Mazur no longer spends class time at the board doing problems. He says this shows something that may seem obvious.

“If you understand the material better, you do better on problem-solving,” Mazur says. “Even if there’s less of it done in class.”

Peer instruction has proven effective in a range of subjects from psychology to philosophy.

A Skeptical Audience

College students typically come into peer instruction courses skeptical.

“Basically my entire life I have been in a situation where a teacher stands up and talks and then you take notes and try to absorb the information as well as you can,” says Ryan Duncan, a sophomore in Eric Mazur’s physics class at Harvard.

“I’ve developed a pretty good system to deal with that and revamping my entire education ‘philosophy’ for this one class was a bit daunting.”

But Duncan says he has come to appreciate Mazur’s approach.

His classmate Stacey Lyne says she has too. She says it will be frustrating to go back to the traditional approach when she takes classes from other teachers.

“I know I’m frustrated now with some of my other classes when I go to lecture and I have to just sit there and take in information and I don’t really get the opportunity to think about what I have just learned,” she says. Lyne says she’s learning more in this new way.

But getting Lyne’s other professors to stop lecturing will be a hard sell. Change is slow in the academy, and professors tend to be rewarded for focusing on their research, often at the expense of their teaching.

By Emily Hanford from American Public Media’s “American RadioWorks®”, © 2011 American Public Media. Used with permission. All rights reserved.

Don’t Lecture Me: Rethinking How College Students Learn 20 February,2012MindShift

  • Heather Wolpert-Gawron

    Welcome to the club, higher education!  

    I believe that there has been such disrespect for those in k12 education trickling down from educators in grades 13+.  It’s been a poo-pooing of these strategies that we in K12 have adopted long ago.  

    “Sage on the stage” is SOOO 1950s.  Teachers in k12 have been working and studying long and hard to be academics both in content and in content delivery.  Being able to communicate one’s content is what makes an educator.  That does not mean standing in front of a group of students and becoming frustrated that they somehow aren’t absorbing a lecture. As Bill Ferriter says, “Maybe it’s not that they are bored, but that you’re boring.”  The content alone is not enough to keep learners engaged.  The educator must also educate, and not look down on the learners for what it takes to trigger that engagement.

    It’s a hard pill to swallow and one that we are always working to get down.  

    I have a friend who left teaching middle school in order to pursue her masters and doctorate at a high level, well-known, competitive university in Los Angeles.  As a TA, her cohort of students have been scoring higher than any other in her program, including those working with the actual professor.  When asked how she was doing it, she replied, “I’m using the strategies I used when I taught Middle School.  I’m teaching.”  She had them work in groups, analyze rubrics, interact with each other and the material.  

    I recently was working with an educator in higher education who claimed that teachers and professors in colleges and universities are the “last bastion” of academia.  Whereas the way I see it, that comment is indicative of the thumbing of noses that happen our way, disrespecting the amount of studying needed to become at expert in both content and communication.

    Some of the achievement gap between K12 and higher ed is in the leap in methodologies between the two, not necessarily in the ability levels of the students.  

    Thanks for this post and for working to articulate our educational system in a way that is more aligned to the needs of our student learners.

    -Heather Wolpert-Gawron
    aka Tweenteacher

    • Aj

      Wow, so Harvard has “discovered” the Socratic Method???

      • Thesciguy

        The oldest and the best.

      • Chris

         hahaha yep – repackaged goods 😉

  • Jfrazz87401

    This seems like a “duh” to me
    except for the fact the vast majority of educators still lecture even
    when presented with ample evidence lecturing is the least effective way
    for students to learn…

    • Beyondtool

      This sounds a lot like flip learning where the lectures are the homework. There is plenty of information out there on this topic if you google it. Personally I’m using blackboard 9 this year to personalize my teaching methods to suit my students. I haven’t really flipped anything yet but I’m working towards it!

  • Kory M Smith

    I am in scale-up physics now and I think it is absolutely terrible. I believe this method is possibly more effective when combined with some lecture but Penn State Behrend (Erie, PA) goes to hell with the joke and offers zero lecture. (Unless you call the teacher flying through the answers in the last 10-15 minutes a lecture) Like lecture courses, a peer instruction class is only as good as your peers. I feel I am literally teaching myself and using much more time for the class to the point where it’s to the detriment of my other courses. I attended weeks of every single supplemental lecture as well. To my shock and horror they are forced to do that in a scale-up fashion too! One 1 hour session there were 9 of us poor souls in there eager to learn physics and it took us the entire hour to go through 1 problem because the TA refused to show us anything (We were clearly clueless and needed SOME direction). By the time we figured it out, you forget how you got from A-Z.  Too much of anything is not good and the university is stubborn to the point of unwillingness to compromise. The learning is incredibly disorganized because I learn little bits and pieces but have difficulty ever putting them all together. A structured lecture would help with this! I think one two hour lecture class, the next 2 hour hands on lab, then the 50 minute class on Friday for the quiz/more hands on if you like. Why I pay thousands of dollars for this 4 credit course when I could of bought the book on amazon, sat at home and struggled to come up with my F=ma equation from my free body diagram is beyond me. If this method is so great then why don’t my peers just teach me calculus then. Why are professors even needed in the first place? I’m being a bit facetious but seriously! This is coming from someone with over 150 college credits in school now for a second degree, not a lazy freshman who just wants a social life. I have gladly posted my real name if anyone at Penn State Behrend wishes to discuss this, I know the professor surely doesn’t want to hear it as I am not the first one who is furious about this. If I do not pass this semester, I’ll take it over and pass it for sure but what a waste of time and money!

    • HardTruth

       Gosh Kory – fancy having to actually do some work to learn something! I know it would make your life easier if your lecturer spoon fed you the information so you can rote learn it for just long enough to pass the exam, but that isn’t why he’s there. If he’s a true educator he wants you to discover the answers rather than being given them to come to know the material not just memorise it. If you’re looking for the easy way out maybe you should just buy the book from Amazon. Maybe you’re not ready for the richness of the educational opportunity you’re being presented with.

    • Active learning is deeper learning. Listening passively to the lecture is partial learning. We were on a visit to the University of Michigan for my daughter on Monday, and I observed a traditional lecture from the back. All laptops in front of students, 20% on Facebook, many others following things other than the lecture or note taking. Traditional lecture doesn’t work any more. Many teachers are still not comfortable with other modes of instruction, but something has to give. Discussion does put more burden on the student, and if students don’t engage, everybody loses. But if students do buy in, they get much more than a traditional lecture-based course. It’s just like every other class-you have put some effort into it to get something out of the experience.

  • William

    I think to poo poo lectures is akin to academia poo pooing group discussion and the like. As an educator as well, i recognise the value of both discussions and of lectures. Instead of completely banking on one style, we need to observe and vary the style for different groups of student. We learn the way we have learnt all our lives. A systemic change is needed before any particular method is to be considered ‘better’ then another.

  • Elaine Johns


    I find this very interesting. People talk about
    “Flipped Classroom” in today’s educational arena and here Harvard
    physicist Eric Mazur shows exactly how the very concept of flipped classroom techniques
    came about years ago. My “ah hah” moment just happened. I was looking for
    “Flipped Classroom” topics, examples and ideas for our Oklahoma Distance
    Learning Conference this April and I flipped right to the very webpage that I
    needed. Mr.  Mazur provides some
    excellent explanations of Peer to Peer learning along with statistical data to
    show it works.  The video is excellent
    and gives great examples of why lectures are not always the solution

    • Waw thats a great teacher and when students understand their concepts it is easy to remember and make more practice becouse when they do not understand they will email any questions that may do not understand. waw that is a great learning

  • Manaliseth

    We have it starting in India too now but a lot of successful schools still opposing it outright! Hope the benefits are for all tosee so that it can be uniformly implemented throughout the country!

  • I hope that some of your site. I just so. Thank you very much for him. We hope to get better in the future. The eye.

  • This is andragogy. Read the theories of Malcolm Knowles, Cyril Houle and Alan Tough.  Visit the International Society of Self-Directed Learning at and read their journals.
    College students (average age 25) and adults in the workplace do not respond well to pedagogy.

  • Student

    University of Rochester has done this for decades. We actually have weekly workshops for most science courses led by mostly undergraduate TAs who have taken the class before. It’s around 10 students each working together for an hour or two to get through the problems, actually applying what was just taught in lecture. Having undergrads instead of graduate students leading these workshops also give it a more comfortable, relaxing feeling that promotes learning.

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  • burkie765

    I think that is very helpful. My physics professor does it but he is somewhat intimidating and shows favoritism and for me that just makes me turned off from the being there in class and from even wanting to learn Physics, I wish I had Manzur! 🙂

  • See “Cognition, Affect, and Learning” for some further insight on the learning process.

  • Julie

    great piece – check out the official Peer Instruction blog – for a quick start guide to flipping your class with Eric’s methods and more stuff.

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