One of my most vivid memories from middle school was in English class. The class wasn’t paying attention to the teacher — we were chattering during “work time” and she wanted us to stop and return to a full-class lesson. So she shouted “SEX!” We all shut up immediately and stared at her in disbelief. Then she said, in a calm, normal voice: “Now that I’ve got your attention …” and proceeded with her lesson. It worked great — except for one thing. I have no recollection of what she actually taught us that day.
This brings up an interesting point: Teachers are often tempted to bring up interesting but irrelevant details (like SEX) in order to maintain student interest in a lesson. But does this actually help students learn the material better? Several studies indicate that it does not. Adding extraneous, unrelated anecdotes can actually distract students from the task at hand and lead to poorer recall, even if they are more “interested” in the material.
But a secondary question about extra details in course materials has yet to be answered: Is it the fact that extra details are present at all which leads to poorer learning? Or does the kind of extra details matter? Are students “seduced” by sexier examples, therefore missing the primary point of the lesson?
A team led by Richard Mayer created two different versions of a lesson on how viruses attack humans. In one version, each major point of the lesson was interrupted by an interesting anecdote such as this one:
A study conducted by researchers at Wilkes University in Wilkes-Barre, Pennsylvania, reveals that people who make love once or twice a week are more immune to colds than folks who abstain from sex. Researchers believe that bedroom activity somehow stimulates an immune-boosting antibody called IgA.
In the other version, boring anecdotes were used instead:
A virus is about 10 times smaller than a bacterium, which is approsimately 10 times smaller than a typical human cell. A typical human cell is 10 times smaller than a human hair. Therefore, it can be concluded that a virus is about 1,000 times smaller than a human hair.
How were the anecdotes chosen? A set of 38 statements related to viruses was rated for interest level by 34 intro psych students (1=”very boring”; 7=”very interesting”). The six most interesting statements (mostly about sex or death) were included in the “interesting” version of the task, and the six most boring statements (random virus facts) were included in the “boring” version.
A new group of 89 students read the materials in one of three formats: a booklet, a PowerPoint show, or an animated presentation, with a time limit about five minutes. Then they were tested in two ways. First, a retention test measured their general knowledge of the lesson. They were given four minutes to answer the question “based on the lesson you just read, describe how a cold virus attacks the body.” Next, they were given a transfer test, to see how well they could apply the information in the lesson, with five questions like “what would happen to viruses if the cells in our bodies developed thicker membranes?”
So how did they do? This graph shows the results:
The students did equally well on the test of general knowledge, whether or not the extra details were interesting. But when they were asked to apply that knowledge, arguably a more difficult task, the students who saw the boring extra details performed significantly better, whether the information was presented in booklet, PowerPoint, or animated form.
In a second experiment, with a completely different example (the digestive system), students were given as long as they liked to read a PowerPoint presentation, and the results were the same.
So while students can get the general gist of a topic when there are irrelevant examples, they do better at applying that information when those examples aren’t very interesting.
Sexy examples, it seems, distract from the learning task. The researchers aren’t suggesting that teachers start using boring examples, either — what’s best is to present only information that’s relevant to what’s being learned. Adding in irrelevant examples, especially the juicy ones, only makes learning more difficult.
There are some limitations to this study. In a lesson lasting just a few minutes, getting students to pay attention is probably easier than during a longer learning session. Those sexy, if irrelevant, examples might help students stay on-task for the longer term. And maybe the problem is one of balance. In the study, the irrelevant materials were about 30 percent of the total material presented. Maybe if attention-getting examples could be reduced to, say, 10 percent of the total, they’d serve their purpose without getting in the way of learning.
Richard E. Mayer, Emily Griffith, Ilana T. N. Jurkowitz, Daniel Rothman (2008). Increased interestingness of extraneous details in a multimedia science presentation leads to decreased learning. Journal of Experimental Psychology: Applied, 14 (4), 329-339 DOI: 10.1037/a0013835