Some Tufts professors work to integrate student participation into physics lectures

    This is the second article in a two-part series examining teaching techniques in college-level physics courses. The first part, which was printed in yesterday's paper, examined some of the bold leaps that other universities have taken to improve instruction and understanding. This installment will focus on efforts being made at Tufts to demystify physics.
    Engineers, pre-med students and other science majors on campus are intimately familiar with Robinson 253, the introductory physics classroom at Tufts, home to Physics 1 and 2. As students sleepwalk into their 8:30 and 9:30 a.m. classes, many are unaware of the research and work that has been put into the lectures they sit through.
    Universities across the country have been actively examining and redesigning their science lectures and curriculums, and Tufts is no exception.
    Professor Roger Tobin has been teaching physics courses at Tufts since 1995, experimenting and tinkering with different ways to teach lecture classes. He began teaching traditional lectures but soon came across research that found that large lectures were ineffective for teaching students.
    "For most of the physicists I knew, the goal was to give clear, well-organized, transparent, logical lectures — preferably with some elegant demonstrations," Tobin said. "But all of the literature shows that even if you do that … only about 30 percent of the class gets it — what you need to do is engage the students."
    Tobin explained that much of the research behind involving students in lectures suggests that students work in small groups on projects. But practicality is another issue. "It was all wonderful, but when I have a class of 200 students, how do I do [that]?" he remembers asking himself.
    Tobin did not have to look far to find techniques to improve traditional lectures. Former Tufts Physics Professor Ron Thornton had been researching students' conceptual physics understanding and developed Interactive Lecture Demonstrations (ILDs). Thornton recognized that large lectures are a reality at many universities and designed ILDs as a teaching method to maximize the effectiveness of large lectures.
    Now the director of the Tufts Center for Science and Mathematics Teaching, Thornton has been conducting research on Tufts' physics lectures since the late 1980s. In line with other educational research at the time, he found that post-tests of conceptual physics understanding given at the completion of physics courses often showed little more than a 10 percent gain over pre-tests given to students before the lecture course began.
    Thornton was shocked by his results. "It just showed that students didn't know what was going on," Thornton said. "[They] were getting through just on knowing algebra and calculus."
    Thornton spent the next few years developing ILDs as a way to create a more active learning environment in large classes. In these demonstrations, the lecturer describes a brief experiment that he or she will perform in front of the class, such as two different-sized blocks colliding to demonstrate Newton's Third Law of Motion. Before conducting the experiment, however, the lecturer asks students to predict the results as a way to actively engage them and to get them thinking conceptually about the lesson.
    Using this pedagogy actively engages students in the lecture, while getting them to think conceptually about the tested principle. Once the experiment is run, students are able to compare their hypotheses to the actual results, further solidifying the concept and challenging their expectations.
    Thornton tested these lecture demonstrations at Tufts with new conceptual pre- and post-tests and noticed substantial improvement. "Students in Physics 1 were going from 10 percent to 90 percent [conceptual improvement]," he said. "We thought our results were too good, but when we tested it again [at the University of] Oregon, we got the same results."
    As Tobin was looking for ways to improve his lectures, he studied Thornton's research along with findings of other professors. Harvard University Professor of Physics Eric Mazur, profiled in yesterday's article, has also sent out a book on peer instruction techniques for lectures to physics faculty; Tobin borrowed some of Mazur's methodology for his courses.
    In current physics lectures on campus, professors use a variety of teaching methodologies. "All instructors are different, I don't know if everyone can or should use these techniques … I don't advocate making it mandatory for every professor," Tobin said. "Some might be more effective using traditional methods, but things I found effective have been working."
    Tobin personally employs techniques from a number of sources. He has incorporated experiments into his lectures — following Thornton's ILD practices — and has students discuss problems posed in lecture in conjunction with Mazur's Peer Instruction method. To employ these techniques, Tobin has used electronic clickers in his lectures.
    While students may have a love-hate relationship with their clickers, Tobin feels that the questions posed to the class really engage students, encouraging them to think and talk among themselves about concepts, rather than passively listen to their professor. The polling results from the clickers also show professors how many students understand a concept.
    Still, both Thornton and Tobin agree that it is not the clickers or any technology that makes the pedagogy work. "There's a tendency to fixate on the technology," Tobin said. "I was doing this type of teaching [with flashcards] 10 years before clickers … The important part is what is going on between students. I'm a bit old-fashioned, I guess, but most of learning goes on between human beings. Technology may in some ways facilitate that, but it does not fulfill it."
    Thornton agrees. He explained that while Technology Enabled Active Learning (TEAL), the physics lecture program at the Massachusetts Institute of Technology, is a useful and successful program, it is not practical because of its cost. "[TEAL] was a very good program to develop, but it took a lot of money," Thornton said. He argues that similar results can be accomplished in regular classrooms without spending millions of dollars.
    In regard to more interactive lecture formats, Tobin is optimistic. "Students aren't doing worse … than traditional [lectures]," he said. "Worst case is [that] they're learning as much and enjoying it more, and I think they're actually learning more."
    In the meantime, Thornton spends much of his time training professors and teachers in workshops and promoting ILDs in national and international educational conferences. "Ordinary physics teachers aren't trained to be teachers, they're trained to be researchers," he said. "Will they do everything we teach? No, but this helps."