CAMBRIDGE - Pop quiz question one: You have a metal plate with a hole in it. You microwave the plate. Does the hole grow, shrink, or stay the same?
Question two: If Harvard University physicist Eric Mazur lectures a class of highly intelligent students on how atoms move away from each other in response to heat, then asks them question one, how many give the wrong answer?
Most of them, it turns out, because one of the least effective ways to teach is to stand in an auditorium and deliver a monologue on facts, as Mazur did in explaining the motion of atoms. In other words: Lectures, the dominant mode of instruction in classrooms, just do not work, no matter how smart your students are.
On Friday, Mazur posed question one to a group of Harvard professors who indeed mostly got the answer wrong. Then he proceeded to show the group exactly why his lecture had been so ineffective, by teaching in a different way. (More on what he did - and on the correct answer to question one - in a bit.)
The group had convened in Harvard’s Northwest Science Building for a one-day symposium on learning and teaching, the first salvo in a $40 million attempt by Harvard to rethink education.
The initiative’s proximate goal is to make Harvard’s teachers better, but the ultimate goal is much more ambitious: to improve education beyond Harvard Yard, perhaps in ways that cannot yet be foreseen.
“We’re going to experiment with lots of things. Some of them will work, and some of them won’t work,’’ Harvard president Drew Faust said in a phone interview yesterday. “But students are inventing new ways of doing things that will change classrooms, no matter what we do.’’
At the symposium, many professors argued for making classes more interactive and moving them online.
Michael Sandel, a Harvard political philosopher, showed off a video-chat format linking his Cambridge classroom with counterparts in Shanghai and Tokyo.
Cathy Davidson, visiting from Duke University, said every professor who can be replaced by a computer screen should be - a comment several audience members immediately tweeted.
There are analog ways of improving education, too, as speakers on the science of learning reminded the audience.
Physicist and Nobel laureate Carl Wieman told the group to stop teaching by instinct and start paying attention to the evidence of what works.
Henry Roediger, from Washington University in St. Louis, offered some of that evidence. He showed a series of experiments from his psychology lab, demonstrating that the best way to ensure learning is to give lots of tests, in every class meeting if necessary.
Bad news for Harvard undergraduates or good news, depending on how one looks at it: several professors at the symposium said they were taking that particular message to heart.
At the meeting’s final panel, several speakers pointed out that there was an elephant - really, a small herd of elephants - in the room.
For instance, Lawrence Bacow, a Harvard board member and former Tufts University president, raised the question of how schools are going to pay for all this exciting change while keeping tuition in check.
Also, said Mazur, was not this group preaching to the choir? Symposium attendees were clearly interested in innovative teaching, but what about people outside the conference room who might be more resistant, who might prefer to keep giving lectures, as they always have? How, he asked, could this group come up with new teaching techniques that would spread?
The key, audience members agreed, would be to get people excited.
That was something Mazur knew how to do.
Take that business about the plate with a hole in it, from earlier in the day.
After his first, failed attempt at teaching atomic dynamics by lecture, Mazur asked his audience members to talk amongst themselves. Then he had them vote on the answer. He told them to envision people standing in a circle who all want to be further away from each other. (What do they do? They step away from the center of the circle.) He asked them how they would get a troublesome lid off a jar. (Stick it under hot water.)
Everyone in the audience murmured and grinned. This time they all understood the correct answer. The hole gets bigger.