College students spend a lot of time listening to lectures.
Eric Mazur: At least until Gutenberg, the only valid approach to education was the lecture.
But experts say the lecture has outlived its usefulness.
Joe Redish: If all there is is lectures, we don't need faculty to do it. Get 'em to do it once; put it on the web; fire the faculty.
Research shows lecturing has never been effective. Now a new college is re-thinking everything about how students are taught.
Tim Horn: We are giant guinea pigs in this huge experiment.
Don't Lecture Me: Rethinking the Way College Students Learn from American RadioWorks.
The lecture is one of the oldest forms of education there is, says University of Maryland physics professor Joe Redish.
Redish: Before printing, it was very difficult to create books, and so someone would read the books to everybody who would copy them down.
Eric Mazur: At least until Gutenburg, the only valid approach to education was the lecture... In fact [laughs], ironically, the word lecture comes from the Latin "to read."
Mazur and Redish are at the forefront of a movement trying to change the way college students are taught. They say lecturing has never been a very effective teaching method. And now that information is so easily accessible, Redish says students need to get more than facts and formulas when they come to class.
Redish: With modern technology, if all there is is lectures, we don't need faculty to do it. Get 'em to do it once, put it on the web, and fire the faculty.
Redish says there is more that professors could be doing to help students learn - and to help them learn better. And he says professors should be doing more because today's
We're going to explore what's wrong with the traditional lecture and the surprising story of how some physics professors figured it out. We'll hear about what they learned, what they did about it, and how their work is influencing a new generation of educators who are trying to invent a different kind of college.
Mazur: I just mimicked what my instructors had done to me. I think that's what we all do. I, I sort of projected my own experience, my own vision of learning and teaching which is what my instructors had done to me. I projected that on to my students. So I lectured.
And he loved to lecture - being on stage in front of a big audience was a huge ego trip. Mazur's students apparently loved it, too. They gave him great evaluations and his classes were full.
Mazur: So, for a long while, I thought I was doing a really, really good job.
But then in 1990 he came across a series of articles that had been published in the American Journal of Physics.
Mazur: Most students know Newton's second law, "f equals m-a." Force equals mass times acceleration.
Harvard professor Eric Mazur says while most physics students can recite Newton's law and even use it correctly to solve problems, the conceptual test developed by David Hestenes and his graduate student at Arizona State shows that most physics students never really understand what the law means, or how to apply it to real world situations.
Hestenes first gave the test - now known as the Force Concept Inventory - to about 1,000 students in introductory physics courses taught by seven different instructors at two different schools. Students took the test at the beginning of the semester. Perhaps not surprisingly, they didn't do very well. They took the test again at the end of the semester. And they still didn't do very well. Their scores went up by only about 14 percent - meaning that after an entire semester, they understood only about 14 percent more about the fundamental concepts of physics than they had at the beginning. When professor Eric Mazur read the article describing these results, he shook his head in disbelief. The test covered such basic material. He was sure the students in his class at Harvard knew this stuff.
Mazur: So I gave it to my students only to discover that they didn't do much better. In fact, when they looked at the test that I gave to them, some students asked me, "How should I answer these questions? According to what you taught me, or according to the way I usually think about these things?" That's when it started to dawn on me that something was really amiss.
What Mazur and other physicists have come to understand is that one reason it's hard for students to learn physics is that they come into class with a very strong set of intuitive beliefs about how the physical world works.
Mazur: And we can function quite well using these intuitive beliefs, right? We can push a chair on the floor, we can throw a ball in a basket; we can catch a ball even though we've never studied parabolic trajectories and even though we've never really understood forces and friction. So we all have these intuitive notions of forces, trajectories and so on, which serve us well in life.
It turns out though that many of these intuitive notions do not square with what physicists have discovered about how things actually work. Most people's intuition tells them if you drop two balls of different weights from the second story of a building, the heavier ball will reach the ground first. But it doesn't - and this is a very difficult concept for most students to understand because they already have a concept in their mind that's in conflict with this new concept.
Mazur: Once you understand physics you can connect those two concepts and you can see everything as part of a coherent set of laws and framework of laws. I think that what many students in their introductory physics courses do is they retain their intuitive notions. They memorize the framework and parrot it back but never really connect the two.
When Mazur realized that many of his students were leaving his class without really understanding physics, he was shocked. The Force Concept Inventory has now been given to tens of thousands of students around the world and the results are virtually the same everywhere. The traditional, lecture-based physics course produces little or no change in most students' fundamental understanding of how the physical world works. Even students who can solve physics problems and pass exams leave the traditional lecture class with many of their incorrect, intuitive notions intact. So how does anyone ever become a physicist?
Hestenes: It's true that we have produced a lot of excellent physicists. But if you look at what's happening in the introductory classes, even at the best schools, the classes only seem to be really working for about ten percent of the students. And I maintain, I think all the evidence indicates, that these ten percent are the ten percent of students that would learn it even without the instructor. They essentially learn it on their own.
And it's not just physics students who have to teach themselves. Research shows the traditional lecture - where students sit and passively absorb information - is not an effective way for students to learn any subject. It may seem obvious that lecturing isn't the best method to get students thinking and learning, but it's the primary way many students are taught, especially in the sciences. It's just the way teaching has been done for a long, long time, and when college was for a relatively elite and small number of people - and science was for an even more select group - most people didn't notice that the lecture wasn't working. The students who were motivated to learn, did. If the rest never understood the material very well it didn't matter that much. But it matters now, says Brian Lukoff who's working with Eric Mazur to improve how physics is taught.
Brian Lukoff: We want to have a class where everyone can be successful because we need everyone to be successful. We need to educate a population to compete in this global marketplace. We can't do that by taking our population and just sort of picking out ten percent and saying, "Oh, you know, you guys are going to be the successful ones and the other 90 percent will do something else." You know, we need a much larger swath of that population to be able to think critically and problem-solve.
The physics class that Eric Mazur teaches at Harvard is now completely different than it was 20 years ago. It's just before 9:30 in the morning. Korean pop music is blaring in the lecture hall as students arrive for class. Mazur says music helps wake the students up. In this class, they will not be listening to a lecture. They are going to be doing a lot of the talking.
Mazur: OK, let's begin...
There are about 100 students in this class. Today they're learning about electromagnetism.
Mazur: So consider a simple parallel-plate capacitor whose plates are given equal and opposite charges and are separated by a distance "D"...
Professor Mazur is reading a question to the class. There are three possible answers projected on a screen. When Mazur is done reading, the students get a minute to think about the question and then answer it using a mobile device that sends their responses to Mazur's laptop.
Twenty-nine percent of the students have chosen the correct answer. Everyone else has chosen one of the wrong answers. Instead of telling the students what the answer is, Mazur instructs them to turn to each other and talk about the question.
Mazur: Go ahead, talk to your neighbor.
Male student: Um, yeah I wasn't actually too comfortable with this question.
Female student: I wasn't either.
Male student: I remember in the book though it said that um, so a capacitor connected to a battery, um, has like a set...
After a few minutes, Professor Mazur tells the students to answer the question again.
Mazur: So wrap up your discussions and enter what you now believe to be the correct answer.
This time, 62 percent of the students get the question right. Next, Mazur leads a discussion about the reasoning behind the correct answer. It's a kind of mini-lecture that includes lots of back and forth with the students. Then the process begins again with a new question. This is a method of teaching that Mazur calls "Peer Instruction." He began teaching this way in the early 1990s in response to how poorly his students did on the Force Concept Inventory, or FCI.
Mazur: I was discussing with my students this FCI...
Mazur was going over a question that half his students had gotten wrong. It was such a fundamental concept that he decided to devote a large chunk of class to re-teaching the idea. He delivered a detailed lecture, put all kinds of diagrams up on the board...
Mazur: I thought I'd nailed it, OK. I thought it was the best explanation one could possibly give of this question. And I triumphantly turned around...
"Any questions?" he asked. The students just stared at him.
Mazur: Nobody raised their hand and said, "Well but what if this or what if that," simply because they were so confused they couldn't. 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 that I don't exactly remember I said to them, "Well why don't you discuss it with each other?" And something happened in my classroom which I had never seen before. 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, most of the students seemed to have a much better understanding of the concept he'd been trying to teach.
Mazur: The 50 percent who had had the right answer effectively convinced the other 50 percent. And I think the reason for that is that if you 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, you know, she has the right reasoning. But, this is the irony, Mary is more likely to convince John than Professor Mazur in front of the class, because she's only recently learned it and still has some feeling for the conceptual difficulties that she has whereas professor Mazur learned it such a long time ago, to him it is so clear that he can no longer understand why somebody has difficulty grasping it. That's the irony of becoming an expert in your field. It becomes not easier to teach, it becomes harder to teach because you're unaware of the conceptual difficulties of a beginning learner.
Student (to other student): Did you end up changing or did you stay the same?
Mazur (to lecture hall): OK...
Student (to other student): What did you put?
Mazur (to lecture hall): The two most popular answers are A and B so I would like to have somebody articulate the reasoning for each of those answers. Do we have a volunteer for either B or A?
Eric Mazur now teaches all of his classes using peer instruction. He doesn't prepare lectures. He teaches by questioning.
Mazur: And what we found over now close to 20 years of using this approach is that the learning gains at the end of the semester nearly triple.
Male student: Um, so I was thinking, draw a Gaussian surface around the insulated material?
Female student: OK.
Male student: And then the amount of charge inside is "Q."
There is a whole field of education research that has emerged from what physicists like Eric Mazur at Harvard and David Hestenes at Arizona State have been figuring out about how students learn. There are now Physics Education Research groups at dozens of universities, and a long list of peer-reviewed studies that confirm what physicists have found about the problems with the traditional lecture. Mazur's peer instruction method is one of the approaches developed in response; other teachers have developed different approaches. But they're all alike in one significant way, says David Hestenes.
Hestenes: The key thing is students have to be active in developing their knowledge. They can't passively assimilate it.
The fact that people learn better when they're actively engaged is one of the central findings from an explosion of cognitive research conducted over the last several decades. Another major finding is that short-term memory is very limited - your brain can only store so much at once. A lot of the information presented in a typical lecture comes at people too fast and is quickly forgotten. Eric Mazur says lecturing is a waste of time. It's not an effective way for students to learn information; reading the textbook is better.
Mazur: In my approach, I leave the information-gathering to the student, before class and in class we work on trying to make sense of the information. Because if you stop to think about it, that second part is actually the hardest part. And the information transfer, especially now that we live in an information age, is the easiest part.
This requires that students do the assigned reading before class - and if you talk to college students in large lecture classes - especially science classes - this is not something many of them are accustomed to doing. They attend lecture to learn what information the instructor thinks is important, then they go to the textbook to read up on what they didn't understand. To get the students to read before class, Mazur has set up a web-based monitoring system where students have to answer questions about the reading prior to class time. The last question is always the same:
Mazur: Please tell us what you found difficult or confusing about the reading. If you did not find anything difficult or confusing, tell us what you found most interesting.
Mazur has a staff of graduate students and post-docs to help him sort through the reading responses. It's from the question about what students found confusing that Mazur and his staff generate the questions used during class. Mazur says having a teaching staff makes it easier to implement peer-instruction, though he insists that after an initial period of extra effort, peer-instruction is actually less work than preparing for lecture classes. But the idea that it takes any extra effort or resources is a big barrier at many colleges says, Michael Doyle, chair of the chemistry department at the University of Maryland College Park. Budgets are being cut and Doyle says it's hard to get anything new started.
Michael Dolye: This is the era we're into efficiencies. You know you're expected to do 120 percent of what is rationally possible and to do it with 30 percent less funding, of course.
Doyle says he's observed classes that take an active-learning approach, but even if he had more resources, he's not convinced doing away with the traditional lecture is the right way to go.
Doyle: One of the things that has always concerned me and for which I've never received an answer is to the question of when you go to this, uh, student-initiated sorts of investigations where you learn by actually discovering things yourself, you must remove from the syllabus a large fraction of what one normally covers in lecture-oriented courses.
This concern - that moving away from lectures means students won't learn as much material - is one of the first things professors ask when Eric Mazur gives talks about peer instruction. Mazur's answer is that you probably won't cover as much material - but that's OK, because he says education doesn't need to be about covering material anymore.
Mazur: For example, when I took my exams they were closed book, you know, you were not allowed to use anything, maybe you could use one sheet with a few equations on it. But you had to know it all. And in fact, until probably about 20 years ago, I needed to know most of the information because I couldn't afford to walk to the library to look up anything. Now, if I need to know a constant or something, I just type it in my web browser, in Google, and a few seconds later I have the information to a higher accuracy than I would have ever have been able to retain.
Mazur believes the purpose of education is changing. It used to be about mastering a certain amount of knowledge. But knowledge is growing and changing at such a rapid rate that it's impossible to learn it all. The key now is to find and use information, not remember and repeat it. And Mazur says the goal of educators should be to help students develop the skills to understand all the new information that will be coming at them throughout their lives. In other words, the purpose of education now should be to learn how to learn. Mazur and other leaders in the field of physics education research say physics can be a good way to do this.
Peter Shaffer: One of the goals of a physics course is not just to teach the subject matter. But we believe you can also teach reasoning; you can teach critical thinking in a physics class.
This is Peter Shaffer, a physics professor at the University of Washington. Shaffer says a key skill for every citizen in the information-age is:
Shaffer: ... to recognize when you do understand something and when you don't. When you're just taking it for granted and when you really understand something that's going on. And trying to have that happen in science departments and physics departments is something that we are trying to achieve.
Lillian McDermott: And most people don't see their role that way, most of our colleagues. It's not that they would deny it's important, it's just, that's, uh, you learn that someplace else.
This is Lillian McDermott, also at the University of Washington and one of the pioneers in the field of Physics Education Research. She first got interested in how college students learn physics by thinking about how young children learn. What she noticed is that kids ask lots of big questions - like this one she got years ago from her daughter when they were in the car one night.
McDermott: Question was, "What keeps the moon up there?"
Like most parents who end up fielding this kind of question, McDermott was caught off guard.
McDermott: And I don't remember what I said, I really don't. But the reason I gave that example - people, they quit asking those questions after they're of a certain age.
McDermott says when children go to school many of them become accustomed to thinking about learning as memorizing facts and they often lose sight of the big picture. By the time they get to a college science class, they're in the habit of putting aside what they're confused or curious about. They focus on learning the information and solving the problems. The way most instructors approach the teaching of science, this is all students are required to do. McDermott says it's not until students make it to upper-level science courses - or even graduate school - that they get to tackle the most exciting and profound questions, like what keeps the moon up there. But by then, a lot of students have given up on studying science. McDermott is convinced more people would stick with science if introductory classes were taught differently. But Joe Redish at the University of Maryland says most professors are not going to change their approach.
Redish: The reason that they don't change it is because there is strong pressure on them not to do that.
Redish says the message most professors get from their departments is this:
Redish: Your research matters; your teaching you can get by with. Our department wants to be the best physics department it can be. The evaluations of those rankings are based on your research. Until the perception of the quality of a department begins to depend on how innovative and creative it is in teaching, it's going to be hard to make that change.
Redish says you have to be a bit of a rebel - and it's a good idea to have tenure already - if you're going to make big changes in the way you approach your teaching. But lots of faculty would like to be more effective in the classroom, says Julie Schell. She works with Eric Mazur and wrote her dissertation about why more professors don't adopt interactive teaching techniques. She interviewed faculty members in science, math and engineering. They told her they spend a lot of time thinking about how to improve their teaching but they're typically doing it quietly, on their own, without much information about what really works. Very few get training or coaching. Schell says at universities teaching tends to be viewed as a private enterprise - something professors don't discuss.
Julie Schell: I had a research question: "Tell me about a time when you've talked this much about your teaching?" Universally they would say, "I've never talked about my teaching like this. No one's ever asked me."
And when professors do make changes to the way they teach, often the stiffest opposition comes from the students.
Ryan Duncan: I had my reservations about how I would like this class.
This is Ryan Duncan, a sophomore in Eric Mazur's physics class.
Duncan: 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, you know, absorb the information as well as you can, so I've developed a pretty good system to deal with that and, you know, kind of revamping my entire education, you know, philosophy for this one class was a bit daunting.
But Duncan has come to appreciate Mazur's approach and says he's learning more in this class than he did in the other physics class he took at Harvard. His classmate Stacey Lyne says she's learning more too and she adds:
Stacey Lyne: I haven't fallen asleep in this lecture, or had the desire to.
Male student: That's really true. That's really true.
Lyne: Because... when you're interacting, I think it's the best way, because it kind of breaks up the lecture.
Lyne says going back to learning in the traditional way will be frustrating.
Lyne: 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 for an hour and a half and I don't really get the opportunity to, um, think about what I have just learned.
[MUSIC: "Porcelain" - Moby - Play & Play: The B-Sides - Downtown]
Stephen Smith: You're listening to an American RadioWorks documentary, Don't Lecture Me. I'm Stephen Smith.
Harvard students like Stacey Lyne would likely succeed in college no matter what kinds of classes or educational environments they were in. Experts say those who have the most to gain from changing the way students are taught are people who have not done as well in the traditional system, or might not have gone to college at all a generation ago. But existing institutions are slow to change. That's why one group of educators decided to create an entirely new college - where there are no lectures.
[MUSIC: "The Keyboarder" - Session Victim - Left the Building - Delusions of Grandeur]
Tim Horn: We are giant guinea pigs in this huge experiment.
To read more about research on how people learn and to see a video of Harvard professor Eric Mazur giving a talk called "Confessions of a Converted Lecturer," visit our web site, AmericanRadioworks.org.
It's been more than a generation since a group of pioneering physicists began documenting problems with the traditional lecture. Harvard professor Eric Mazur expects people at colleges and universities will continue to resist doing away with the lecture, but he believes change is needed now more than ever.
Mazur: This is probably the best possible time to make changes in our approach to education, specifically because of the information age and because of the availability of technology and because of the ubiquitous-ness of information, I mean it pours out of everywhere, right?
Mazur says professors have to accept that they're no longer the powerful sages and sources of information they once were.
Mazur: That role might have disappeared, but there is a much more important role now, namely helping the students make sense of that information.
