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May 30, 2002

SECRETS of teaching large classes REVEALED

You're driving down a hill. A child steps out into the street ahead of you. You hit the brakes. Your car stops well short of the child, but a cop gives you a speeding ticket anyway.

Should you fight the ticket?

That's one of the real-world questions that Pitt physics professor Chandralekha Singh poses to her large-enrollment classes to get students talking among themselves about physics concepts she has covered in lectures.

Singh and other Pitt faculty members shared some of their teaching techniques on May 17 during a day-long Summer Instructional Development Institute on "Teaching Larger Classes."

In exploring whether to challenge the speeding ticket, Singh asks her students to pair up and discuss between themselves facts that she provides: the car's speed and mass, the posted speed limit, the grade of the hill, and the distance the car traveled after its brakes were applied (as measured by skid marks). Singh adds extraneous details (the road's width, for example) so her students learn to focus only on relevant data.

"It's a mechanics question but it's so much more interesting for [students] to do it in this context," Singh said. "It really gets the students talking to each other."

She asks students to work in pairs, rather than groups of three or more, to minimize the possibility that shy or lazy students will sit back and let other classmates do all the talking — not that Singh grades students' work during these exercises. "I emphasize that there is no penalty for a wrong answer. I tell my students, 'This is intended only to help you learn.'"

Singh and other panelists emphasized the need for "active learning" in large classes: combining lecture segments with short-duration group discussions, games and problem-solving exercises aimed at helping students to master course material and keep them from zoning out. According to articles distributed to institute participants, studies show that:

* The average adult's attention span is 20 minutes, at most.

* Lecture classes appeal only to auditory learners, as opposed to those who learn better visually or through direct involvement in activity.

* Students in lecture-based college classrooms are attentive only about 60 percent of the time. And, while students retain 70 percent of the material covered in the first 10 minutes of a lecture, they retain only 20 percent of the last 10 minutes.

Some professors shy away from active learning exercises because they believe that they have too much material to cover, and can't afford to interrupt their lectures. But such teachers confuse coverage with learning, said institute panelist David DeJong.

"When I came here [to Pitt in 1989] I had this interest in teaching everybody everything I knew," said DeJong, an economics professor. "It doesn't take long to figure out that you may have said a whole lot, but you didn't teach a whole lot.

"I probably cover about 70 percent of the content today that I did in 1989, but I think my students are better economists when they come out of my classes today."

DeJong and other panelists stressed the importance of telling students, early in the term, exactly what will be expected of them. For his large-enrollment macroeconomics courses, DeJong's goal is to train students as macroeconomists. "I don't want them to just be able to recite formulas like: If interest rates are cut, output will tend to rise. I want students to know why….When the Fed cuts interest rates by a quarter of a percent, I want them to be able to explain to someone on the street, or at a party or wherever, why [the Federal Reserve Board] did that, what are the implications, what are the potential benefits, what are the potential costs."

DeJong initially taught large-enrollment macroeconomics courses through lectures only. He soon found that his students were learning macroeconomic models but couldn't apply them to real-world situations. He then adopted a hybrid approach, combining lecture segments and small-group exercises.

"To me as a teacher, the most beneficial thing about these exercises is that they allow me to understand exactly where students are having trouble, right away," DeJong said. "And, it helps provide immediate feedback to the students as to the difficulties they're having so that, when I unleash them on homework assignments, they're in a much better position to do the problems themselves."

Active learning faces several impediments in the School of Law's large-enrollment classes, said law professor Lu-in Wang: Law students tend to be competitive and resist cooperative, supportive peer learning. Most intend to specialize in certain types of law, and groan at the thought of studying, say, contracts and civil procedure — subjects that Wang happens to teach. Also, many students bring their laptop computers to class; lacking cutoff switches in the law school's larger classrooms, faculty can't keep students from checking e-mail or playing computer games during lectures, Wang said.

But the legal profession, by its nature, does encourage the use of role playing, which Wang said can be applied to teaching larger classes in her school as well as others. In classroom exercises, Wang assigns students to take on the three roles associated with their future profession: advocate, counselor and judge.

"As an advocate, you are responsible for representing your client's interests. Your personal point of view and preferences don't matter," Wang noted. Preparing an argument (and sometimes, in quick succession, a counter-argument) as an advocate encourages students to master complex material, said Wang. It also de-personalizes classroom discussions of controversial issues such as abortion and affirmative action, she said.

"I may ask my students, 'How would you argue if you were the lawyer for a plaintiff who is seeking to challenge an affirmative action policy?' Or, 'How would you argue if you were counsel for a university that is seeking to uphold an affirmative action policy?' That enables the student not to be viewed as the person who holds that opinion, but instead as doing what a professional does — that is, using the principles and rules of law in order to support a position that a client would like to see upheld."

In the roles of counselor and judge, students gain a broader, less partisan view of the law, Wang said. Breaking off in mid-lecture, and assigning students to argue the merits of a case from the viewpoints of advocate, counselor and judge "often generates very excited discussion," she said.

Discussions during the May 17 institute yielded a number of teaching tips, including:

* Randomly calling on students to answer questions, rather than asking for a show of hands. This keeps less attentive students on their toes, and encourages less outgoing ones to participate. An alternative: Asking a student to close his or her eyes and point toward a fellow student; the student pointed to must answer the question.

* Encouraging students to prepare mock-cheatsheets. If you can boil down course material in a form small enough to fit on your palm, wrist or a bit of paper, you should be able to memorize and master it, faculty said.

* Instructing students to hiss when a lecturer is going too fast, or an important point isn't understood. Students in large classes may fear that raising their hands or voices will make them seem thick-headed to their fellow students, but hissing can be done in relative anonymity.

The May 17 institute was presented in collaboration with the Office of the Provost and the Provost's Advisory Council on Instructional Excellence.

— Bruce Steele

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