Image Image Image Image Image

Coherence Principle


Designers may be tempted to add background music, other sounds, extra graphics and additional text to help make the e-Learning more interesting, keep learners engaged or to appeal to a particular demographic of learners.  In this chapter, the authors explain how to use the coherence principle in e-Learning to “avoid adding any material that does not support the instructional goal” (Clark & Mayer, 2011, p. 151).  The basis for this principle is the cognitive theory of multimedia learning and the idea the learners have dual channels for processing information:  auditory/verbal and visual/pictorial.  Using both channels engages the cognitive processing necessary for learning, but the capacity of these channels is limited.  If one is overloaded, learning can be negatively impacted.

To avoid cognitive overload, the authors provide the following recommendations:

Coherence Principle 1:  Avoid e-Lessons with Extraneous Audio – Designers should avoid adding background music or other extraneous sounds to instruction because in situations where the learner is unfamiliar with the content, the instruction is delivered at a rapid pace and/or the learner cannot control the pace, the learner may experience cognitive overload.  A learner’s auditory channel capacity is limited, so if narration is competing with background music or other unnecessary sounds, learning can be negatively impacted.

Coherence Principle 2:  Avoid e-Lessons with Extraneous Graphics – Evidence shows that learning is not improved by pictures and videos that are only added to decorate the page, screen and content.  Extraneous graphics and related captions can distract the learner and interfere with the learner’s ability to make sense of the e-Learning content.  Justifying the use of extraneous graphics with claims that they are necessary to appeal to the next generation of learners raised on high-intensity multimedia is not supported by the evidence of experiments using young adults.  The authors also recommended that visuals included in instruction should be simple “with fewer details presented at one time” (Clark & Mayer, 2011, p. 164).

Coherence Principle 3:  Avoid e-Lessons with Extraneous Words – To prevent distractions, designers should keep text short, clear and concise.  Extraneous words may be added for a variety of reasons, but the authors focus on three – for interest, to elaborate and to add technical depth and generally recommend avoiding them in all of those cases.

In summary, evidence shows that learning may be hampered by the distractions and/or cognitive overload caused by extraneous materials, but there is still much to learn about the coherence principle and its impact on a variety of learners since most studies were focused on novices.

Clark, R. (2002, September 10), Strategies and Techniques for Designers, Developers, and Managers of eLearning, The e-Learning Developers’ Journal, pg. 6
Long, M. (2013, February 17), The Coherence Principle by Meichelle Long,
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,
Rutschke, A. (2013, April 9), EDTECH 513:  Coherence Principle Analysis, EDTECH Learning Log,