On Friday, October 30, the Center for Educational Resources launched our Lunch and Learn—Faculty Conversations on Teaching series with two faculty presenting on developing and using effective active-learning exercises in their classes.
Vince Hilser, professor and chair, Department of Biology led off with a presentation [presentation slides] describing how he had used active learning to help students understand a core concept, equilibrium, in his Biochemistry course. Showing his sense of humor, Hilser presented a timeline for the first semester he taught the course in 2011: August—Hilser prepares (brilliant) lectures. September, October, November—Hilser delivers (brilliant) lectures to students. January 2012—Hilser receives student evaluations and realizes that students did not learn from (brilliant) lectures.
Convinced that understanding the principle of equilibrium would enable students to truly learn it, Hilser wondered if he could help his students actually see an example of equilibrium. A classic demonstration of equilibrium is the so-called Apple Wars: An apple tree straddles the properties of two neighbors with yards separated by fences. Every fall the tree drops its fruit and the old man and young man throw the unwanted apples into each other’s yards. Ultimately, as they are throwing, the number of apples on each side will reach a constant state, which is at equilibrium.
In Hilser’s classroom (a large lecture hall), a long line of yellow police caution tape running from front to back stood for the fence. Ping pong balls represented the apples. Students on one side were the young man and could fetch and throw with both hands, on the other side, the old man students were handicapped by being allowed to fetch and throw with the left hand only. A blast from a whistle started the students throwing ping pong balls across the fence, retrieving and throwing back. At the end of a timed sequence the balls were gathered on each side and counted. The exercise was repeated and the results echoed those of the first round. Then Hilser introduced the equation for equilibrium, filling in the results from the ping pong war demonstration to demonstrate the application of variables. Once the students have seen in real life what equilibrium is, the equation make sense to them. They can then move on to methods of inquiry and how biological systems work.
Hilser could see from course assessments that students had a firmer grasp of the concepts. Evaluations showed that 86% of the students felt that the apple wars demonstration was effective in helping them to understand and apply the concept of chemical equilibrium. Students trusted the facts because they had experienced the proof. One student commented, “This really made me believe that organized randomness occurs in nature,” a statement that shows a high level of perception and extrapolation. Hilser’s presentation demonstrated that a good active-learning exercise can be worth more to students than a lot of words from the sage on the stage.
Todd Hufnagel, Professor in the Department of Materials Science and Engineering, presented [presentation slides] on his experience with using peer instruction in his Structure of Materials course. This class typically has 20 to 25 students.
In 2011 Hufnagel received a grant from the National Science Foundation (NSF). In response to the broader impacts requirement, he decided pursue an educational research project. For Hufnagel, a core principle underscores his teaching philosophy as articulated in this quote from Herbert A. Simon: “Learning results from what the student does and thinks and only from what the student does and thinks.” The grant allowed him to test whether student learning outcomes would be better if the course was taught using an active-learning model or using a traditional lecture style by teaching it twice each way in alternating years.
He turned to a model developed by Harvard’s Professor of Physics, Eric Mazur, involving the use of concept inventories and peer learning. “A concept inventory is a criterion-referenced test designed to determine whether a student has an accurate working knowledge of a specific set of concepts.” Students are given a concept inventory test at the beginning of the semester and again at the end of the semester to measure their learning gains.
During the semester, the concept questions are used as a basis for peer instruction. Hufnagel introduces a slide with a multiple choice question. Students use their clickers to vote on what they think is the correct answer. Hufnagel shows them a histogram of all the answers. If the histogram indicates that students are confused as to the correct answer, he asks students to discuss the question in pairs of small groups. Based on the idea that the best way to learn something is to teach it, students who know the correct answer will explain the concept to those who don’t.
After discussing the question, the students are asked to vote again. The instructor can then determine the level of understanding and proceed with a full explanation, a quick clarification, or simply affirm that the students are correct and move on to the next concept.
Is active learning better? Hufnagel’s comparison of teaching the class two ways showed that improvement in concept inventory scores in lecture version of class was 63%, for the active learning classes the improvement was 100%. He also surveyed the students about how their confidence in understanding the material. Interestingly, the lecture course students rated their knowledge much higher than the active learning students. Hufnagel thought this is because the active learning setting makes students realize how much they don’t know, while the lecture course students aren’t as aware of what they don’t know.
Hufnagel detailed the pros and cons of using a peer-instruction approach. On the plus side, students learn more, and the instructor gets more effective feedback on what they students actually know as s/he circulates through class listening to their discussion. Hufnagel also noted that this approach was much more fun for him as a teacher. The drawbacks are that it can be more difficult to “cover the material,” and there is a significant time commitment on the part of the faculty. For the first, Hufnagel noted that the important thing is that students understand the material that is covered, and that students can be made responsible for learning some of the content outside of class. As to the second, while it is easier and faster for faculty to write lectures, once the concept questions are written, they have a long shelf life and can be re-used. In the end, the strong evidence of improved student learning gains with active learning is a compelling argument for using these teaching strategies.
Faculty attendees had questions and made comments during the discussion period. Following is a summary of some of the main points.
On ways of handling coverall “all the material,” Hufnagel assigns reading and watching videos outside of class. He finds the students like the videos as they can tackle content on their own schedule and repeat as often as needed to understand the material. There is quick four question quiz on the assignment to encourage students to both do the work and to help them retain the concepts. Research tells us that students learn by being asked to recall content frequently. He spends the first five minutes of class talking informally, perhaps brining in a topical information to increase interest, then spends the rest of the class on concept questions. Typically he will get through about six questions per class. He tells his students that he has data that show students learn better with active learning and that helps with buy-in to what may be a new learning experience.
To faculty questioning how much time had to be allocated for active learning exercises, Hilser explained that the ping pong ball demonstration takes an entire class, but it establishes an understanding of a concept so fundamental to the course that is it worth the time spent.
A question, “What about teaching the facts? What if students don’t absorb enough factual knowledge?” led to a response by Hilser that there are many facts that are critically important as base knowledge, absolutely required facts. But he and Hufnagel agreed that beyond the core facts, students can look up information. The instructor’s role is to provide context.
One attendee noted that he has participated as an instructor in a department where lecture and active learning course covering the same content are running in parallel. The active learning class do slightly better (10%) on exams, but they are much happier in class–more satisfaction is seen in the active learning students.
Johns Hopkins Krieger School of Arts & Sciences and Whiting School of Engineer faculty will receive email invitations for the forthcoming Lunch and Learn presentations. We will be reporting on all of the sessions here at The Innovative Instructor.
Macie Hall, Senior Instructional Designer
Center for Educational Resources
Image sources: Lunch and Learn logo by Reid Sczerba, Center for Educational Resources. Other images were taken from the presentations by Vince Hilser and Todd Hufnagel.