The redundancy principle: explaining graphics with audio and redundant text can hurt learning.
Some e-Lessons provide words in text and in audio that reads the text. This might seem like a good way to present information in several formats and thus improve learning. Controlled research however, indicates that learning is actually depressed when a graphic is explained by a combination of text and narration that reads the text.
In studies conducted by Mayer and by others, researchers have found that better transfer learning is realized when graphics are explained by audio alone rather than by audio and text. Mayer found similar results in two studies for an average gain of 79%.
There are exceptions to the redundancy principle as recently reported by Roxana Moreno and Mayer. In a comparison of a scientific explanation presented with narration alone and with narration and text, learning was significantly better in conditions that included both narration and text.
The researchers conclude that, “An effective technique to promote broader learning with multimedia explanations is to use the auditory and visual modalities simultaneously for verbal information if no other visual material is presented concurrently.” Therefore there will be limited situations in which narration of onscreen text could be helpful to learning such as when there is no graphic on the screen or when readers lack good reading skills.
As illustrated in Figure 5, overload of the visual and auditory components of working memory occurs if an on-screen graphic is explained by both text (which enters the visual center) and narration. However if there is no on-screen visual, then overload would not result and because dual codes would be provided, learning would be increased.
Figure 5 Presenting words in text and audio can overload working memory in presence of graphics.
In general, it’s advisable to avoid narration of text when there is a demanding visual illustration on the screen. This is especially important when working memory is subject to overload such as during an animation in which learners have limited control over the pacing, or during the presentation of complex new information. In contrast, when there is no graphic information on the screen, then research to date would suggest that presenting words in text and auditory format would benefit learning.
The coherence principle: using gratuitous visuals, text, and sounds can hurt learning.
It’s common knowledge that e-Learning attrition can be a problem. In well-intended efforts to spice up e-Learning, some designers use what I call a Las Vegas approach. By that I mean they add glitz and games to make the experience more engaging. The glitz can take a variety of forms such as dramatic vignettes (in video or text) inserted to add interest, background music to add appeal, or popular movie characters or themes to add entertainment value.
As an example, consider a storyboard for a course on using statistical quality control techniques to improve quality, shown in Figure 6. To add interest, several stories about the costs of product recalls were added. But how do these additions affect learning?
Figure 6 A seductive detail from a quality lesson. From Clark and Mayer, 2002.
In the 1980’s research on details presented in text that were related to a lesson explanation but were extraneous in nature found them to depress learning. Such additions were called “seductive details.” In more recent research, Mayer has found similar negative effects from seductive details presented either via text or video. For example, in the lesson on lightning formation, short descriptions of the vulnerability of golfers to lightning strikes and the effect of lightning strikes on airplanes were added to the lesson.
In six of six experiments, learners who studied from the base lesson showed much greater learning than those who studied from the enhanced versions. The average gain was 105%. Similar effects were seen in a comparison of lessons that included background music and environmental sounds with base lessons that did not add extra auditory material.
Finally, a third series of experiments compared an expanded explanation that used 500 words and several captioned illustrations with a lesson that used only the illustrations and their captions. Students who received the summary version — just the visuals and their captions — actually achieved 69% more learning.
Mayer did several studies together with S. F. Harp to determine why seductive details depress learning. In these experiments they evaluated the hypotheses that these added materials did their damage by:
- Distracting learners from key instructional points,
- Disrupting the learner’s organization of information into a coherent mental model, or
- Activating irrelevant prior knowledge.
They created three versions of lessons that included seductive details but that also added instructional methods that should compensate for their damaging effects. Only one of their compensatory treatments reduced the negative effects of the seductive details. Seductive details placed at the beginning of a lesson were more damaging than the same information placed at the end of the lesson.
Therefore, they concluded that these details activate inappropriate prior knowledge. Since learning takes place by the integration of new information into existing knowledge in long-term memory, stimulating inappropriate prior knowledge would have a damaging effect.
The coherence principle essentially tells us that “less is more” when learning is the primary goal. It suggests that visuals or text that is not essential to the instructional explanation be avoided. It suggests that you not add music to instructional segments. It also suggests that lean text that gets to the point is better than lengthy elaborated text.
As designers we need to make a distinction between entertainment and learning. This is not to say that an effective e-Learning course is not interesting. Mayer reminds us of prior distinctions between cognitive interest and emotional interest. Cognitive interest stems from materials that promote understanding of the content presented — in other words from materials that optimize learning. Emotional interest comes from the addition of extraneous materials which have been shown to depress learning. Our goal should be to promote cognitive interest and avoid emotional interest in situations that require cognitive learning processes.
The personalization principle: Use conversational tone and pedagogical agents to increase learning.
A series of interesting experiments summarized by Byron Reeves and Clifford Nass in their book, The Media Equation, showed that people responded to computers following social conventions that apply when responding to other people. For example, Reeves and Nass found that when evaluating a computer program on the same computer that presented the program, the ratings were higher than if the evaluation was made on a different computer. People were unconsciously avoiding giving negative evaluations directly to the source.
Of course individuals know that the computer is not a person. However, deeply ingrained conventions of social interaction tend to exert themselves unconsciously in human-computer interactions. These findings prompted a series of experiments that show that learning is better when the learner is socially engaged in a lesson either via conversational language or by an informal learning agent.
Based on the work of Reeves and Nass, Mayer and others have established that learning programs that engage the learner directly by using first and second person language yield better learning than the same programs that use more formal language. Likewise a number of studies have shown that adding a learning agent — a character who offers instructional advice — can also improve learning.
While some computer scientists are working to make agents very realistic, a series of studies using Herman the Bug (see Figure 7) as an agent found that:
- The appearance of the agent made little difference — a cartoon or human worked just as well.
- Learning was better when the agent’s words were presented in audio rather than in text and in a conversational style rather than in a formal style — congruent with the modality and personalization principles.
- The agent did not even need to be visible on the screen — the voice alone was sufficient to promote better learning.
Figure 7 Herman the Bug is a pedagogical agent. From Clark and Mayer, 2002.
Learning is based on an engagement of the learner with the content of the instruction. Even though learners know that computers are inanimate, the use of conversational language either directly in the program or via an agent seems to stimulate very ingrained unconscious social conventions that lead to deeper learning.
When you are in a conversation with someone you are expected to listen and respond in a meaningful way. This requires you to invest attention in what the person is saying, to process it and to generate a meaningful response. A similar model seems to apply when learners see the e-Learning as an engagement with a social partner — even an inanimate one.
When you write the script for your e-Lessons, use first and second person constructions, but don’t over do it. For example, dialog such as, “Hey Dude — Are you ready for some exciting information on quality control tools?” is incongruent and more distracting than helpful. The research on pedagogical agents is quite new so applications are still a bit tentative. First, it seems that you don’t need to invest a lot of effort in the physical representation of the agent. Second, you need to consider the role of the agent. To be useful the agent needs to serve an instructionally valid role — not just appear as an on-screen character.
One example I liked is shown in Figure 8. In this program designed to teach reading comprehension at a fourth to sixth grade level, the agent Jim is introduced and appears throughout the program to show readers comprehension strategies that have worked for him.
Figure 8 Jim serves as a pedagogical agent. With permission from Plato Learning Systems.
So there you have it. These six media element principles should give you the basics since all e-Learning programs must rely on some combination of graphics, text, and audio to deliver their content. Perhaps now that you better understand the research that has been done, the psychological foundations of why the principles work and have seen some examples of how the principles are applied you will feel more confident in using them yourself.
Clark, R.C. and Mayer, R.E. (2002). E-Learning and the Science of Instruction: Proven Guidelines for Consumers and Designers of Multimedia Learning. San Francisco: Jossey-Bass Pfeiffer.
Clark, R.C. (1999). Developing Technical Training: A Structured Approach for Developing Classroom and Computer-Based Instructional Materials. Silver Spring, MD: International Society for Performance Improvement.
Harp, S.F. and Mayer, R.E. (1998). How seductive details do their damage: A theory of cognitive interest in science learning. Journal of Educational Psychology, 90 (3), 414-434.
Kalyuga, S., Chandler, P., and Sweller, J. (2000). Journal of Educational Psychology, 92 (1), 126- 136.
Moreno, R. & Mayer, R.E. (2002). Verbal redundancy in multimedia learning: When reading helps listening. Journal of Educational Psychology, 94 (1), 156-163.
Reeves, B., & Nass, C. (1996). The Media Equation. New York: Cambridge University Press.