1, 2012 from APM
lecture is one of the oldest forms of education there is.
printing someone would read the books to everybody who would copy them
down," says Joe Redish, a physics professor at the University of Maryland.
lecturing has never been an effective teaching technique and now that
information is everywhere, some say it's a waste of time. Indeed, physicists
have the data to prove it.
Eric Mazur began teaching physics at Harvard, he started out teaching the same
way he had been taught.
sort of projected my own experience, my own vision of learning and teaching
undefined which is what my instructors had done to me. So I lectured," he
loved to lecture. Mazur's students apparently loved it, too. They gave him
great evaluations and his classes were full.
a long while, I thought I was doing a really, really good job," he says.
then in 1990, he came across articles written by David Hestenes, a physicist at
Arizona State. Hestenes got the idea for the series when a colleague came to
him with a problem. The students in his introductory physics courses were not
doing well: Semester after semester, the class average never got above about 40
noted that the reason for that was that his examination questions were mostly
qualitative, requiring understanding of the concepts rather than just
calculational, using formulas, which is what most of the instructors did,"
had a suspicion students were just memorizing the formulas and never really
getting the concepts. So he and a colleague developed a test to look at
students' conceptual understanding of physics. It's a test Maryland's Redish
has given his students many times.
a question from the test: "Two balls are the same size but one weighs
twice as much as the other. The balls are dropped from the top of a two-story
building at the same instant of time. The time it takes the ball to reach the
ground will be..."
possible answers include about half as long for the heavier ball, about half as
long for the lighter ball, or the same time for both. This is a fundamental
concept but even some people who've taken physics get this question wrong.
get to the answer, Redish went to the second floor of the physics building. A
group of his students was on the sidewalk below. When he reached the top, he
dropped two balls from the roof.
two balls reached the ground at the same time. Sir Isaac Newton was the first
person who figured out why. He came up with a law of motion to explain how two
balls of different weights, dropped from the same height, hit the ground
most physics students can recite Newton's second law of motion, Harvard's Mazur
says, the conceptual test developed by Hestenes showed that after an entire
semester they understood only about 14 percent more about the fundamental
concepts of physics. When Mazur read the results, he shook his head in
disbelief. The test covered such basic material.
gave it to my students only to discover that they didn't do much better,"
test 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.
classes only seem to be really working for about 10 percent of the
students," Arizona State's Hestenes says. "And I maintain, I think
all the evidence indicates, that these 10 percent are the students that would
learn it even without the instructor. They essentially learn it on their
says that listening to someone talk is not an effective way to learn any
have to be active in developing their knowledge," he says. "They
can't passively assimilate it."
is something many people have known intuitively for a long time undefined the
physicists just came up with the hard data. Their work, along with research by
cognitive scientists, provides a compelling case against lecturing. But with
budgets shrinking and enrollments booming, large classes aren't going away. You
don't have to lecture in a lecture hall though.
physics class is now different. Rather than lecturing, he makes his students do
most of the talking.
a recent class, the students undefined nearly 100 of them undefined are in small
groups discussing a question. Three possible answers to the question are
projected on a screen. Before the students start talking with one another, they
use a mobile device to vote for their answer. Only 29 percent got it right.
After talking for a few minutes, Mazur tells them to answer the question again.
time, 62 percent of the students get the question right. Next, Mazur leads a
discussion about the reasoning behind the answer. The process then begins again
with a new question. This is a method Mazur calls "peer Instruction."
He now teaches all of his classes this way.
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," he says.
value of this approach is that it can be done with hundreds of students. You
don't need small classes to get students active and engaged. Mazur says the key
is to get them to do the assigned reading undefined what he calls the
"information-gathering" part of education undefined before they come
class, we work on trying to make sense of the information," Mazur says.
"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."
approach is one of many developed in response to evidence that traditional
lectures don't work. Among the advocates of these approaches there's an
increasing sense of urgency about how to help more students do better.
need to educate a population to compete in this global marketplace," says
Brian Lukoff, an education researcher at Harvard. "We can't do that by
just sort of picking out 10 percent and saying, 'Oh you guys are going to be
the successful ones,' and you know we need a much larger swath of that
population to be able to think critically and problem-solve."
ask anyone involved with efforts to lose the lecture and they'll tell you they
encounter resistance. Sometimes the stiffest opposition comes from the students.
my entire education, you know, philosophy for this one class was a bit
daunting," says Ryan Duncan, a sophomore in Mazur's class.
he adapted and says he learned more in Mazur's class than he did in his other
physics course at Harvard.
Redish says when he lays out the case against lecturing, colleagues often nod
their heads, but insist their lectures work just fine. Redish tells them
undefined lecturing isn't enough anymore.
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
faculty are threatened by this, but Mazur says they don't have to be. Instead,
they need to realize that their role has changed.
used to be just be the 'sage on the stage,' the source of knowledge and
information," he says. "We now know that it's not good enough to have
a source of information."
sees himself now as the "guide on the side" – a kind of coach,
working to help students understand all the knowledge and information that they
have at their fingertips. Mazur says this new role is a more important one.
Radioworks is the documentary series from American Public Media. You can
find more of their reporting on this issue at "Don't Lecture Me."