Without active learning, there is no learning

In the following sections I explain how I implemented this philosophy in my upper-division course, Biological Evolution. Biological Evolution was an upper-level undergraduate elective with five prerequisites. As such, it was taken primarily by seniors during their last semester before graduation. Over the years I found that that even advanced biology students bring many preconceptions to this class. The strong anti-evolution sentiment in the Southeastern US influenced at least some of my students, including those who signed up for this course. After teaching the class a few times, I concluded that the students’ preconceptions were not being addressed effectively through a traditional lecture-based approach or using traditional texts. With these approaches students could be taught to memorize the material, but not to engage it at a level where they had to face and overcome their preconceptions. It also seemed to me that many of the problems I saw in the class stemmed from the fact that my students were only able to assimilate advanced material at an introductory level. Their analytic and quantitative skills were underdeveloped. Specifically, the students had difficulty formulating coherent arguments and were only able to interpret the simplest graphs. Naturally, these problems were reflected in their poor writing and speaking skills. In fact, their poor analytical ability may have been due to their failure to learn to write well at earlier stages in their education.

I found the use of traditional evolutionary biology texts problematic because, in an effort to appeal to larger audiences, they have become more comprehensive and now cover topics at a deeper level than many undergraduate students are able to assimilate. Consequently, they have become less accessible to students with weak skills. In my opinion, undergraduate evolutionary biology texts are now more similar to reference books than textbooks. The increased depth of coverage forced me to spend more and more of my lecture time introducing and explaining basic concepts. This meant that the students received more and more pre-digested material, material that they did not have to think about to understand. This allowed them to memorize the material without understanding it. Based on these experiences, I decided to develop an approach where the students were more actively engaged with the material. I felt that this approach would be more effective for higher-level learning, and at the same time would discourage the ineffective learning techniques students often use when taught with traditional methods.

First, I dispensed with standard texts and substituted three books: Darwin’s Origin of Species, 1st ed., a lower-level graduate text Fossils and Evolution by T. S. Kemp, and a CD tutorial on methods of phylogenetic analysis, Skeleton, Smith and Monks, Cladistics: A Practical Primer on CD. I explain my reasons for these choices below. Second, I stopped lecturing. After the first two weeks, all class material was presented by the students. As part of this approach the course required both writing and speaking competencies. The students had to both write and speak well to pass. Third, I gave the students demanding reading and summarizing assignments, and checked their compliance with these assignments at the beginning of each class period. In short, I gave all of the intellectual work in the course to the students and assumed the role of a facilitator and coach.

I chose The Origin of Species as a text for several reasons. The first is its importance in the history of evolutionary thought. No other work approaches the significance of Darwin’s seminal work. This book is especially important for students who doubt the correctness of the theory of evolution. They might be tempted to argue with another author, but few would have the audacity to disagree with Darwin. His stature assures a fair hearing for what he has to say. Fortunately, The Origin is just as relevant today as it was when it was first written. Darwin wrote for a skeptical audience, an audience whose attitudes were not so different from those of my students. He provides the detailed observations and interpretations that are necessary to convince his readers of the correctness of his theory. The wealth of detail in his descriptions and the amount of evidence that he presents for his conclusions make The Origin uniquely suited as an introduction to the theory of evolution. These considerations overrode potential problems with Darwin’s use of Victorian English, and the fact that his understanding of the mode of inheritance is incorrect. To deal with the language problem I developed assignments to help the students break down his long sentences and extended arguments into digestible bits. I also encourage the students to discuss the impact of Darwin’s misunderstanding of the mode of inheritance on his theory of evolution, and think about why this misunderstanding did not have a larger impact on his theory.

I chose Kemp’s book Fossils and Evolution because it takes a conceptual approach to understanding fossils and thus extends the work we did with The Origin. Kemp emphasizes paleontological methods and the assumptions that underlie the interpretation of fossil evidence. Based on my experience with courses that emphasized factual knowledge it seemed unlikely to me that the students would retain much information about fossils after the semester ended. I also knew that even if they did retain the material, it would not generalize to novel situations. Given these limitations, I wanted the students to gain analytic skills that would generalize to new situations, while at the same time learning about evolutionary theory and how evolutionary biologists think. Kemp’s problem-oriented approach is ideally suited to these goals.

The final book I chose for the course is an interactive introduction to the methodology of Phylogenetic Systematics (Cladistics). Skeleton, Smith and Monks’ Cladistics: A Practical Primer on CD is the best introduction to this methodology that I have found. Over the years I have tried many ways to introduce these methods, using a number of different texts. The students uniformly failed to assimilate the material and concepts. The CD uses an interactive format consisting of short audio lectures supplemented with interactive graphics and exercises. Some of the exercises must be printed and done on paper. This active learning approach engages the students in a way that traditional texts do not. Supplemented with in-class exercises, I found the CD to be very effective in conveying the often counter-intuitive concepts of Phylogenetic Systematics.

Having decided on the texts, I needed to develop methods that would allow the students to utilize them effectively. Darwin had an excellent vocabulary. He regularly uses words that either are not in common use today, or that I could not expect my students to know. “Vitiate” and “esculent” are two examples from the first chapter. Darwin also makes frequent reference to organisms which the students do not know. Few students would know what a Cirripede is (a barnacle) or know the difference between a Jacobin and a Runt (two types of pigeon). To help the students deal with this terminology and these organisms, I developed assignments that lead them through the process of reading and assimilating the text.

Prior to dealing with a chapter in class, every student had to complete a Reading Worksheet for the chapter. The worksheet required the students to learn unfamiliar words and organisms, and to annotate the pages of The Origin with their own comments.

During the class periods the students presented chapters of Darwin’s or Kemp’s books and, at the end of the semester, presented the results of their own independent investigation of a contemporary problem in evolutionary biology. The first two speaking assignments were completed and presented by groups of students. The final assignment was prepared and presented by each student independently. This approach gave the students experience in making oral presentations in a safe atmosphere. By dividing the chapters of Darwin’s and Kemp’s books into sections the students could both work together to understand the material, and yet prepare separate presentations. Using this approach the students actively engaged with the material, developed methods for effective group work, and got several chances to improve their speaking skills before their final presentation.

Because the first two presentations were done as part of a group, the students had to be able to relate their section of the chapter to the material that came before and after. The ability to integrate their portion of the material into a larger whole is a high-level cognitive task, similar to the skill they need when integrating a paragraph into a whole paper.

During their first two presentations, I arranged for the students to receive two types of feedback: positive feedback from their peers, and comprehensive feedback from myself. Immediately following a presentation the other students provided written, positive feedback. I did not allow negative comments from other students. This focus on positive feedback allowed the students to develop their speaking skills in a safe environment, and to learn from the strong points of each other’s presentations. I have found it much more effective to allow students to learn from the successes of their colleagues then to provide negative feedback about what they did incorrectly. My own feedback was presented on a grading rubric which I developed for this purpose. The rubric allowed me to easily give students meaningful feedback on the important points of their presentation. I used the back of the rubric to summarize the strengths of their presentation and to note areas that could use improvement. I always strove to give constructive feedback in the most positive way so that students felt encouraged to improve their presentation skills. At the end of a class period I also made general comments about how to improve speaking skills, and modeled specific skills for the class.

The chapter on Phylogenetic Systematics from Kemp’s book was studied in a different way. Before tackling this difficult chapter the students work through several sections of Skeleton et al.’s CD as homework. During class, I reinforced what they learned at home by having them do hands-on exercises taken from Wiley, Siegel-Causey, Brooks and Funk’s workbook The Compleat Cladist. The in-class sessions allowed the students to apply what they have learned from the CD in a context where they could receive assistance and feedback from each other, and from me. I circulated around the class answering questions, checking answers, and checking on students’ progress and comprehension. Throughout the class I asked students to explain their interpretations on the blackboard and used the blackboard and overhead projector to address common questions.

Just after midterm the students were assigned a term paper based on a topic of their choice. The paper had three purposes: To familiarize the students with a segment of the recent scientific literature on evolution; to help them prepare for their speaking assignment at the end of the semester, which was on the same subject; and to help them improve their technical writing skills. Writing the papers was a three step process. First the students prepared a draft of their paper, which was then exchanged with another member of the class for peer-review. The students brought their written reviews to class and discussed them with the author. The reviewers also completed a self-evaluation. I graded the peer and self-reviews, but not the drafts of their papers, which the students rewrote based on the peer-evaluations and handed in one week later. I then read and graded the papers. Students who received above 92% on this draft were not required to rewrite their papers. Those with lower scores were asked to incorporate my suggestions and rewrite their paper during the last weeks of class. During the last few weeks of classes the students presented the results of their research in their final speaking assignment.

Outcomes

The students learned a great deal in the course and become much better speakers. Not only did they learn the evidence for the theory of evolution by natural selection, but they also learned to apply methods for accessing difficult texts and improved their writing and speaking skills. The final presentations were routinely better than the initial ones, and not infrequently better than I hear from my professional colleagues. The re- writes of their papers were also usually considerably better than the first drafts. It is clear that the student’s took the comments of their peers to heart in a way that is difficult to achieve with comments from me.

These improvements were reflected in the final grades. I structure the grading so that more points were awarded at the end of the semester when the students can be expected to have benefited from class activities. I routinely give the students in this class a higher proportion of A’s than in any other of my classes.

Contact me: kirchoffbruce at gmail