Let’s Get Physical

Let’s Get Physical

Berkeley’s new approach to introductory physics gets students excited–and it helps them learn

Colin McCormick

It’s 8 o’clock on a Tuesday morning. 51 Evans Hall is filling up. Students shuffle papers, reading over their notes and homework. At precisely ten past eight, Chris Vale, the Graduate Student Instructor, strides into the room carrying a cardboard box full of two-foot long metal rods and iron clamps. “Well, it’s swordfighting today,” he announces, earning appreciative chuckles from his seventeen Physics 7A students.

As Vale hands out eight-page lab worksheets on rotational inertia and torque, the students divide themselves into groups of twos and threes to tackle the problems with their rods and clamps. The room gets noisy as students talk and argue. One student even pulls off a shoe so that his group can swing rods from the shoelaces to test their worksheet answers. Vale cruises from group to group, answering questions, checking on progress, and taking note of what needs further explanation. For a few minutes he interrupts the students’ work to give a mini-lecture on the moment of inertia, the rotational analogue of mass, but the quiet is quickly broken by the chatter of students resuming discussions and experiments. By the end of the two-hour class, as the students file out and hand Vale their worksheets, everyone has the day’s concepts under control.

For Vale and his 30 fellow Graduate Student Instructors (GSIs) teaching Physics 7A and 7B, this is a typical section meeting. Anyone who taught these required introductory courses for science and engineering majors before 1996, however, might have difficulty recognizing the courses today. Back then, weekly discussion sections lasted only 50 minutes, and consisted mostly of a GSI answering questions about the week’s homework. A different GSI would run the lab section, during which students did standard “cookbook”style experiments, and prepared formal reports of their methods and procedures. Lab and discussion sections were not closely coordinated with the week’s lectures.

In the fall of 1994, however, Dr. Bruce Birkett, a lecturer in the Physics Department, learned an important lesson about student participation and extended class time when he took over teaching the Department’s “Intensive Discussion Sections” (IDSs). These special sections, created by Cal physics PhD Dr. Andy Elby, provided motivated Physics 7A students with the option of two extra discussion sections per week, allowing for additional class participation and discussion. The idea was to give the students challenging problems, while providing them with all the resources and support they would need to work their way through to solutions.

Birkett taught four of these two-hour sections every week in the 1994-1995 school year, and says the experience was “a major revelation. Instead of watching me solve physics problems, students were working through the material for themselves. I was watching them make the material their own.” Pretty soon, the word was out that signing up for an IDS was the first step toward doing well in Physics 7A, and by Spring 1995, the program had over forty students voluntarily enrolled.

Such student enthusiasm led Birkett to think about reforms for the entire 7A course structure. In addition, he had seen that many of the better GSIs were frustrated because their interaction with students was limited by the standard 50-minute discussion sections, and further complicated by the assignment of separate sets of GSIs for discussion sections and labs. Scheduling mismatches also interfered with students’ conceptual continuity between theoretical lessons and experimental work, as students would often perform lab experiments several weeks before or after the topic was presented in lecture.

An opportunity for change came in 1996, when a team led by Dean of Physical Sciences P. Buford Price won a $200,000 grant from the National Science Foundation to implement cross-campus undergraduate teaching reforms. In collaboration with the Chemistry and Mathematics Departments, Birkett helped the Physics Department to design a Physics 7A course based largely on the IDS model. He and GSIs Jason Zimba and Miles Chen designed an innovative set of worksheets and teaching notes to accompany the revamped course. The changes were implemented for Physics 7A in Fall 1996, and Physics 7B one year later.

Birkett and Professor David Weiss, who taught Physics 7A in Fall 1996, worked together to finalize the current “discussion/lab” (DL) structure. Students now attend three hours oflecture per week (as before) and two 2-hour DL sections, led by the same GSI and with the same group of about twenty students. One DL section in four is used for a lab, and the topics are closely integrated with the material in the lecture. Section time is primarily devoted to group work, with students collaboratively answering questions on worksheets as the GSI moves between groups to help with problems and check on progress.

The consolidation of discussion and lab sections and the student participation that it encourages has had a profound impact on the teaching of physics at UC Berkeley. “When I was taught this material as an undergraduate,” says former Physics 7B GSI Andreas Birkedal-Hansen, “the labs often did not overlap the lectures at all, and were therefore almost useless. However, when they are combined in quick succession, it seems students understand the material much better and also recall the information for longer periods of time.”

Students are also able to pursue specific issues or points raised in the lab at their very next section meeting with their GSI, without having to wait two weeks for the following lab. “The hope was that we’d create a way for students to dig in and explore the material for themselves,” Birkett explains. “Introductory physics is tough! But it’s my firm belief that through the right activities, and with good support from their GSIs, our students will thrive.”

And thrive they do. In quantitative terms, UC Berkeley students’ scores on a national test of basic concepts in physics, the Force Concepts Inventory, have increased significantly since the introduction of the DL format. Professors teaching Physics 7A and 7B also have plenty of anecdotal evidence that students in the DL format classes do better on in-class exams than students from years past who took comparable tests. So what precisely is it about the new course structure that translates into improved student performance? Some suggest that the key is the way in which the new course structure enables instructors to do more for their students. “Even if you had an excellent teacher in the traditional format,” notes former Physics 7B GSI Loraine Lundquist, “[he or she] would not be able to do as much in depth exploration of concepts as the new format allows. The added time in class and the teacher support structure—i.e., the lesson plans and insightful worksheets— just make it so much easier.”

Others point out that the mobility and one-on-one interactions of the instructor “cruising” the classroom provide critical real-time feedback for the teaching process, allowing the GSI to interrupt the group work to deliver a mini-lecture, if it becomes apparent that many students are having difficulty with the same point. “I get to know right away if students are ‘getting it’ or not,” says Vale. “In the traditional format, you might talk for an hour and never know if anyone understood a word you said.”

Blume-Kahout notes that the DL format “takes the GSI out of ‘lecture’ role and puts the onus of activity on the students themselves…it’s an effective learning technique for the students, who are supposed to be asking questions and answering them.” Working with peers on conceptual questions has also helped teach students how to communicate their physics knowledge better. “Another advantage of the DL format,” says Vale, “is that I can teach students how to ‘speak Physics.’ It’s amazing how many students can get the right answers but can’t tell you in English why they’re right.”

Birkett is quick to explain that worksheets and teaching notes aren’t enough: “You can have the best [curriculum] materials in the world, but if the teacher doesn’t know how to use them, it doesn’t matter. Supporting the GSIs is crucial.” To help GSIs in their own professional teaching development, Birkett teaches Physics 300, the Department’s graduate pedagogy course. The course is required for first-time GSIs, and it allows GSIs to share observations and comments. These can be quite specific, since everyone teaches from the same worksheets and teaching notes. First-time 7A and 7B GSIs also receive extra pre-semester training to prepare them for going “into the trenches” (as Birkett likes to put it) with their students.

This is the moment when Birkett gets to ask his two favorite questions of his new GSIs: “How do you, a successful graduate student at Cal, learn material that is hard for you?” and “What do you want your students to do to help them learn physics for themselves?” His goal is to help students in his courses develop the same habits as successful graduate students at UC Berkeley. “No teacher can make a student learn anything. Indeed, I read a quote recently that ‘the aim of teaching is to make student learning possible.’ I think I agree,” muses Birkett.

So perhaps the secret of the success of the DL format classes is that the format encourages students to do a better job of helping themselves learn. “In-class participation is really high,” says Vale. “Some of the kids are real hams who are ecstatic to finally have a teacher who actually wants them to talk in class.” Instructors also report surprisingly high attendance for Physics 7A and 7B. “[My students] kept coming to 7A discussion section throughout the term, whereas in the other classes they drifted away as the semester went on,” says former GSI Robin Blume-Kahout.

Vale sums it all up dramatically: “My 8 a.m. section attendance is about 95%, compared with about 50% for my afternoon (old-format) 7A section…And within a few weeks, the whole class is merrily chatting away about—can you believe it—Physics!”

Colin McCormick is a graduate student in physics.