Colleges Cope With Bigger Classes

In their own research, scientists hypothesize, measure _ then use data to figure out what works. But for teaching, "they're immediately willing to make generalizations about the thousands of students who've been through their class based on the two that talked to them last week," Wieman said.

There's no magic bullet, but measurement is the key.

"We're in this new era of engaging in this as a scholarly enterprise," said Noah Finkelstein, a young Colorado physics professor who has worked with Wieman to revamp a class he teaches. "Most faculty haven't been taught education is a scholarly enterprise. Most faculty have been taught education is an art, not a science."

One of the tools of the new science is "clickers," handheld voting devices now used on at least 700 campuses nationwide, according to manufacturer eInstruction. They let teachers pose mid-lecture multiple choice questions and instantly evaluate if students are grasping the material.

During a recent morning lecture in Colorado's General Chemistry 1131, Professor Robert Parson spoke for a few minutes, then posed a multiple-choice question to the class of about 250. The question, like others he used, was designed by a team of science-learning experts with trick choices that signal if students are falling for common misconceptions. The results of the "vote" popped up on an overhead screen. Then, before revealing the answer, Parson had students break into small groups to discuss the answer and vote again. The group did well, and he moved on. If it had performed poorly, he would have reviewed the material.

Perhaps the biggest challenge in college teaching is bridging the gap between an often brilliant expert and students new to the subject. Clickers help remind teachers how a novice sees their material.

"You realize how many people don't know something you forgot you didn't know 20 years ago," said Barbara Demmig-Adams, one of four Colorado professors who teaches a general biology course with 1,300 students and who introduced clickers this year.

Other campuses are trying different ideas, but a common thread is making big classes more of a two-way street.

At Virginia Tech, for instance, most introductory math courses now take place in a giant room called the "math emporium," in a converted department store just off campus. Students rarely if ever meet together. Instead, they come in any time, 24 hours a day, to work through problems on the 500 computer work stations. When they have a question, they flip over a red plastic cup beside their desk, and helpers _ upperclassmen, graduate students or professional staff _ come by.

Despite the roomful of computer hardware, the emporium is a much less expensive way to teach _ for one course about $24 per student, compared to about $77.

Teaching assistants in Parson's chemistry course and at the math emporium say they're growing increasingly confident in these kinds of methods. But some students are still sour on them.

"I can't do it very well with someone teaching me," said Ian Millington, a Virginia Tech sophomore who failed a calculus class but got a B when he took the same course last summer at a local community college. "So how am I going to teach it to myself?"