The "Change-Up" in Lectures

Joan Middendorf and Alan Kalish
Teaching Resources Center
Indiana University

Listen to a colleague reporting on a recent visit:

I sat in the back of the classroom, observing and taking careful notes as usual. The class had started at one o'clock. The student sitting in front of me took copious notes until 1:20. Then he just nodded off. The student sat motionless, with eyes shut for about a minute and a half, pen still poised. Then he awoke, and continued his rapid note-taking as if he hadn't missed a beat.

Not infrequently we observe students having lapses of attention. And we've found that it's not enough for us to tell faculty with whom we are working about the problem. They're often aware of it already. What really makes a difference is for us to be able to offer a little theory, which we will do in this article, and then some concrete suggestions of activities they can use in their classes to break up a particular lecture on a particular day.

One explanation for the lapses in students' attention is that the "information transfer" model of the traditional lecture does not match what current cognitive science research tells us of how humans learn. Research tells us that the brain does not record information like a videocassette recorder. Instead, it handles information by reducing it into meaningful chunks that we call categories. Learning consists of fitting this reduced information into already existing categories or, sometimes, of forming new ones. Categorization determines how a concept is acquired, how it is retrieved from memory, and how it is put to work in abstracting or generating inferences. Examples are a primary means of making connections between old knowledge and new knowledge. Their concreteness allows students to draw connections between the new abstract idea or principle and what they already know.

Once a new concept has been introduced, students need an opportunity to practice thinking in terms of that concept. Right in a lecture class, you can ask students to generate their own example of the concept, summarize it, write an exam question for it, or explain it to someone else. This approach works with the mind's natural processes, and thus improves learning.

Studies on attention span also shed light on why students have difficulty with the traditional lecture format. Adult learners can keep tuned in to a lecture for no more than 15 to 20 minutes at a time, and this at the beginning of the class. In 1976, A. H. Johnstone and F. Percival observed students in over 90 lectures, with twelve different lecturers, recording breaks in student attention. They identified a general pattern: After three to five minutes of "settling down" at the start of class, one study found that "the next lapse of attention usually occurred some 10 to 18 minutes later, and as the lecture proceeded the attention span became shorter and often fell to three or four minutes towards the end of a standard lecture." Other studies appear to confirm these findings.

In 1985 Ralph A. Burns asked students to write summaries of presentations and tallied the bits of

"As the lecture proceeded attention spans became shorter and often fell to three or four minutes towards the end of a standard lecture."

Given that students have an attention span of around 15 to 20 minutes and that university classes are scheduled for around 50 or 75 minutes, instructors must do something to control their students' attention. We recommend building a "change-up" into your class to restart the attention clock. If your main mode of instruction is lecture, clearly the primary activity for most of your students is listening to one person talk; even in whole class discussion, only the student actually speaking at any given time is doing anything other than listening.

Combining what we know about attention span and how the mind works, we suggest that lectures should be punctuated with periodic activities. Johnstone and Percival report that lecturers who "adopted a varied approach . . . and deliberately and consistently interspersed their lectures with illustrative models or experiments, . . . short problem solving sessions, or some other form of deliberate break . . . usually commanded a better attention span from the class, and these deliberate variations had the effect of postponing or even eliminating the occurrence of an attention break." Many of our colleagues also report that when they intersperse mini-lectures with active engagement for students for as brief a time as two to five minutes, students seem re-energized for the next 15 to 20 minute mini-lecture.

By planning exactly when to insert an activity, you can make sure that your students pay the most attention to the issues which you feel are most important. Don't do activities for their own sake; they should be integrally related to giving students practice with the most important concepts in that day's class. So, telling jokes about lawyers halfway through a fifty minute economics class will change students' level of attention, but will add little to their learning of cost/benefit analysis. Varying your approach to teaching also allows you to get your students actively involved in their own learning. The research on the mind gives us the theoretic base for advocating active learning. A large body of literature tells us that when the goal is to foster higher level cognitive or affective learning, teaching methods which encourage student activity and involvement are preferable to more passive methods.

Active learning lets you give your students opportunities in class to practice with the concepts you want them to learn. Particularly effective for getting students actively engaged in the classroom are collaborative learning techniques. What better way to get students active than to have them explain their new knowledge to one another? By making the classroom a social learning experience instead of a solitary one, instructors can reduce the student passivity through which some students seem to hide out in large classes.

Research confirms that breaking down the walls of anonymity promotes learning. One colleague, who teaches journalism, told us that he fell into using small groups by accident, but they generated so much energy and interest in class that he now uses them regularly:

"I wanted to show some slides and have the entire class talk about [them], but the slides didn't get processed in time. So I got half a dozen magazine spreads, and I divided the [students] up into six groups. I was really, really shocked, but delighted, to see what a tremendous wave of energy this released in the class. All of a sudden these students who had been sitting there listening very passively got very energetic; they began to talk to each other, and they were actually doing exactly what I wanted them to do."

When you plan your classes, you will want to decide how often to add a change-up and what activity to use. Use the 20 minute attention span as a rule of thumb: In a 50 minute class, use one change-up in the middle; in a 75 minute class, use two change-ups, at roughly one-third and two-thirds of the way through the class period. But don't follow this slavishly; anything that becomes predictable will have less impact. Variety is a powerful force. Having a handful of activities you can use comfortably will keep the students guessing, wondering what you will do next. Be sure to earmark at least one-third of the time you allow for the activity for debriefing afterwards; this is when most of the substantive lessons of the activity will be confirmed. Without a wrap-up, students see these activities as amorphous and sometimes confusing; a concluding debriefing helps them understand what was important and what was not.