The Coherence Principle

The Coherence Principle is one of several multimedia principles developed by Richard Mayer in several papers (for example: Mayer, 1999; Moreno & Mayer, 2000) and most recently in his book E-Learning and the Science of Instruction (2011).

According to the coherence principle, we learn better from concurrent graphics and audio than from concurrent graphics, audio, and on-screen text, that is to say, when extraneous material (in the case, the written text) is excluded rather than included in multimedia presentations, as extraneous material “may overload working memory and may signal readers to focus on inappropriate aspects of the material.” (Mayer, 1999, p. 620). Briefly, the principle suggests not to add printed text to a narrated presentation.

The coherence principle is based on psychological and cognitive theories and research. Mayer argues that we have separate and limited channels for processing verbal and pictorial materials. When presenting words as narration, and not redundant written text, we avoid overloading the visual channel and extraneous cognitive processing, when for instance students try to compare printed and spoken words.

It is directly related to several other principles discussed by Mayer. The redundancy principle, for instance, suggests that we do not add on-screen text to narrated graphics, because it tends to hurt learning. The split-attention principle argues that we learn better when we are not required to split our attention between multiple sources of information.

There are certain situations, however, that benefit from the use of redundant techniques of on-screen text, called boundary conditions: when there is no pictorial presentation, when there is ample opportunity to process the pictorial presentation, for non native speakers or learners with disabilities, or even when only few words are presented next to a graphic.

I have already watched many powerpoint presentations where the presenter mainly reads what is written on the slides, which do not have graphics. In this case, one channel is not being used (pictorial) and the verbal channel is being overloaded, besides the fact the reading usually flows in a different speed than the presenter spoken words, causing a cognitive dissociation.

I have been trying to use more and more this principle in my presentations, preparing slides full of images and few words, as I will talk during the presentation, so that both channels are being used, without extraneous material and overload.

I believe the Coherent Principle is a wise guide for presentations; however, I am afraid it was developed in a pre-web 2.0, social networks and games era, and many times I find myself wondering if, in a multitask and Flash-like intensive scenario, and anti-powerpoint presentation tendency, it still makes sense.

References

Clark, R. C., & Mayer, R. E. (2011). E-learning and the science of instruction: Proven Guidelines for Consumers and Designers of Multimedia Learning. 3rd edition. Pfeiffer: San Francisco, CA. (Kindle Edition)

Mayer, R. E. (1999). Multimedia aids to problem-solving transfer. International Journal of Educational Research, 31(7), 611-623.

Moreno, R., & Mayer, R. E. (2000). A learner-centered approach to multimedia explanations: Deriving instructional design principles from cognitive theory. Interactive Multimedia Electronic Journal of Computer-Enhanced Learning, 2(2), 2004-07. Retrieved from http://imej.wfu.edu/articles/2000/2/05/index.asp