Incorporating Active Learning in Large Classes

While faculty across the disciplines share an interest in teaching strategies that promote active learning in the classroom, such strategies are often more challenging to incorporate in large, introductory courses. As faculty in the department of physics have found, however, integrating active learning can create an engaging classroom environment that has the potential to improve student learning.

Since 2004, Washington University students have had the option of registering for Physics 197/198, introductory physics courses in which group problem-solving is a major part of each class session. These two courses are taught by Professor Tom Bernatowicz and Senior Lecturer Rebecca Trousil. In contrast to the more traditional, 53-minute lecture format employed in Physics 117/118, each class session in Physics 197/198 combines 10-15 minute “mini-lectures” with interactive problem solving, demonstrations, and conceptual questions. The students in Physics 197/198 tend to be similar to those enrolled in Physics 117/118, with about equal numbers of first-year engineering students and second- or third-year pre-health students.

During the problem-solving portion of the class, students work in small groups to develop solutions to “two-minute” problems. When prompted by the instructor, one student in the group then indicates the group’s solution by pointing to a letter on the back of the textbook. This method allows the instructor to quickly tally the responses and to ask students to explain the rationale behind their responses. The students’ explanations then serve as the basis for further discussion by the whole class. Often, when there is disagreement among the groups, the instructor performs a short experiment or demonstration to shed light on the problem and help the class determine which answer is the best solution.

Bernatowicz and Trousil have found this teaching approach to be quite successful in generating student participation, even as their sections have grown from approximately 60 to 100 students. Typically, all students participate in the small-group discussions, and about 30-40% of the students regularly volunteer to explain their groups’ solutions to the whole class. Bernatowicz and Trousil have also found that, when compared to their experience with the traditional lecture format, the class format in Physics 197/198 is both more fun and more challenging—for instructors as well as for students.

In fact, the active-learning approach in Physics 197/198 requires a significant amount of work on the part of instructors and students. For example, the more extemporaneous style of each class means that Bernatowicz and Trousil must prepare a variety of material and activities, so that they can adapt their teaching in response to students’ questions and ideas. Compared to students in Physics 117/118, who have weekly homework assignments, students in Physics 197/198 are assigned daily and weekly homework, which requires them to have a “steady diet” of physics each day. Rather than consulting the textbook for clarification of concepts that have been taught in lecture, moreover, students in Physics 197/198 must read about the day’s topics and complete two homework problems before coming to class. Students therefore come to class prepared to explore the topics in greater depth. In addition, because they each have a sense of which aspects of the topic they have mastered and which are still unclear, students come to class with focused goals for their own learning.

To encourage students to dedicate time and effort to the homework, incentives are built into the course design. For instance, homework scores count more toward the final course grade than in Physics 117/118. In addition, students have the opportunity to correct and resubmit their homework. The initial score on the homework will indicate that something is incorrect or unclear, but students have to figure out on their own what they need to address before resubmitting the work. If students take short-cuts in this process by simply copying the solution from the solution key or asking someone else how to solve the problem, they find that their performance on the exams suffers. Students therefore learn that to do well in Physics 197/198, they must develop the skills necessary to solve problems in collaboration with others and on their own. 

The impetus for the development of this teaching approach came as a result of a formal departmental review process as well as informal observation by Bernatowicz, who had concluded that students in the introductory physics courses were not learning as much as he had hoped. More specifically, there was evidence that students were completing these courses with highly developed quantitative skills, but without the conceptual reasoning skills that were important to the courses and to subsequent academic and professional work. Furthermore, Bernatowicz was interested in making the introductory courses more interactive.

Looking around for a textbook that took a new approach to the teaching of introductory physics, Bernatowicz settled on Thomas A. Moore’s Six Ideas that Shaped Physics. This textbook presents a curriculum that Moore has developed over two decades, refining his approach as he learns what does and does not work in the classroom. Moore’s thorough treatment of the textbook’s themes, combined with his incorporation of problems that are both “real” and “messy,” provide a means of teaching students to learn to think like physicists. Bernatowicz and Trousil have found that students are initially challenged by this type of problem, which cannot be solved by simply finding an appropriate formula and “plugging in” known values. At the same time, they find that the real-world applications of the problems are intrinsically motivating to the students.

While many students enjoy the interactive class format and the work it entails, some students complain about the heavy workload. Bernatowicz and Trousil find that some of this resistance reflects an expectation among the students that learning involves the transmission of knowledge from instructor to student in a one-way fashion. They attempt to correct that expectation early on in the course by indicating on the course syllabi and in their initial class meetings that the courses require a high level of active student engagement. They also make it clear that making mistakes is a part of learning, and therefore they encourage students to take risks and to “think out loud” when they participate in class activities. Comments by students on course evaluations reveal that, by the end of the course sequence, most of those who say that the workload is too heavy also indicate that they have learned valuable thinking and problem-solving skills and that they have often enjoyed the challenging aspects of the courses.

Encouraged by these initial indications of the courses’ effectiveness and by anecdotal evidence of improved learning, Trousil has recently undertaken a formal evaluation of Physics 197/198 in collaboration with HHMI postdoctoral fellow Lisa Brooks. This study aims to determine whether the active-learning approach employed in the courses leads to increased student satisfaction and improved student learning of quantitative and conceptual reasoning skills. This project, in a pilot phase during the spring 2009 semester, will be fully implemented starting in fall 2009.