CAAA Newsletter — Winter 2006

Educator’s Forum

The Scholarship of Teaching: Student Retention

A plethora of research exists that can help instructors do a better job in the classroom. Below are summaries of two studies focused on how well students retain information. In the first, researchers find that pausing to allow students to absorb what has been said will increase their retention — in essence, if teachers talk less, students learn more. The second study provides evidence that students learn more when there is less new content and more time to reinforce facts and concepts presented.

Lecture Pauses

Ruhl, K. L., C. A. Hughes, and P. J. Schloss. 1987. Using the pause procedure to enhance lecture recall. Teacher Education and Special Education 10 (Winter): 14–8.

In this study, an instructor paused for two minutes on three occasions during each of five lectures: the intervals ranged from 12 to 18 minutes. During the pauses, while students worked in pairs to discuss and rework their notes, no interaction occurred between the instructor and students. At the end of each lecture, students were given three minutes to write down everything they could remember from the lecture (free recall); 12 days after the last lecture, the students were also given a 65-item multiple-choice test to measure long-term retention. A control group received the same lectures (using the same anecdotes and visual aids) and was similarly tested. In two separate courses repeated over two semesters, the results were striking and consistent: students hearing the lectures while the instructor paused did significantly better on the free recall and the comprehensive test. In fact, the magnitude of the difference in mean scores between the two groups was large enough to make a difference of two letter grades (depending on cutoff points)!

The implication of this research is staggering, for it essentially says that if we talk six minutes less, students learn more. Undoubtedly, these counterintuitive results stem from two things: (1) the short lectures (12–18 minutes) are consistent with research that suggests that students’ ability to retain information falls off substantially after 10–20 minutes; and (2) by engaging in an activity that reinforces the information presented, student learning should be increased. This study clearly suggests that we have an opportunity to build short, active-learning activities into our lectures with no loss to the content learned. Indeed, students seem to learn more from the process.

Information Density

Russell, I. J., W. D. Hendricson, and R. J. Herbert. 1984. Effects of lecture information density on medical student achievement. Journal of Medical Education 59 (November): 881–9.

The authors of this study, concerned about the large amount of information available in medical texts and the perceived need by lecturers to cover even more material in the time available, studied the effect of information density on student retention. They prepared three different lectures on the same subject. Ninety percent of the sentences in the high-density lecture disseminated new information. By comparison, only 70 percent of the sentences in the medium-density lecture and 50 percent of the sentences in the low-density lecture presented new information. During the remaining time, the lecturer reinforced material by restating key ideas, highlighting the material’s significance, providing illustrative examples, and relating the material to the student’s prior experience. The lectures were presented to a total of 123 students randomly distributed into three groups, which showed no significant difference in cumulative GPAs. Finally, students were given a pre-test that showed no significant difference in their knowledge base, and two post-tests — one immediately after the lecture, and one unannounced 15 days later.

Statistical results clearly showed that students in the study learned and retained lecture information better when the density of new material was low. The implication is that the amount of new information that students can learn in a given time is limited, and that instructors defeat their own purposes when they exceed that limit. (Who among us has not gone over the allotted class time with “just one more thing”?) The study suggests that instructors would be better off presenting only the basic material necessary to achieve the learning objectives: approximately only 50 percent of the material presented in any lecture should be new. The rest of class time should be devoted to material or activities designed to reinforce the material in students’ minds.

This study is significant since one of the chief barriers always presented by faculty to the acceptance of active learning is that “there is simply too much content to cover”. Apparently, less new content and more time spent reinforcing the facts and concepts presented (which could include active learning) will lead to greater student learning.

To find out more about college teaching and its scholarship, go to http://php.indiana.edu/%7Enelson1/TCHNGBKS.html.