Coherence Analysis

The Coherence Principle states that adding extraneous material into a multimedia lesson hurts student learning, even if the extra material is interesting. “The coherence principle is also based on the idea that learners are more likely to make appropriate connections between animations and narrations when they can hold corresponding visual and verbal representations in working memory at the same time.“ (Mayer, R. E., 1999) Adding extraneous material in the form of audio, graphics or words works against learners who are trying to make these appropriate connections. When designing a multimedia lesson, educators often want to quickly engage and motivate learning by adding in extra “interesting” material that might appeal to and draw in their audience. Unfortunately, research has found that adding in extraneous material that is not directly connected to the specific learning target can create cognitive overload in the learners, thus creating a less effective learning activity.

The Coherence Principle piggybacks on the Modality Principle, which states that a combination of narration and images optimizes cognitive processing via the auditory and visual channels. Once extraneous material is added to either of these channels, cognitive overload and frustration can occur, causing the learning process to be impeded. If the extraneous material is in the form of sound, specifically adding in background music with a narration is one of the worst violations. In a series of studies by Meyer and Clark, their results found that adding background music overworks the working memory, especially if the material is new to the learner or the delivery method is not under their control. According to Meyer and Clark‘s research, learners scored 20-67% better when there was no background music with a narration. “When processing capacity is used to process the music and sounds, there is less capacity available for processing the narration, organizing it into a coherent cause-and-effect chain, and linking it with the incoming visual information.” (Moreno, R., & Mayer, R. E., 2000). Meyer and Clark found similar learning outcomes when environmental sound effects were added, unless these sounds were directly connected to the specific information being presented. Sound effects can be very distracting to learning in a slideshow presentation, especially in the form of sound effects connected to text animation. Some presenters at my staff development meetings add these in to create a sense of “fun”, but the final effect is simply annoying and distracting.

Adding extraneous graphics to a multimedia presentation can also hurt student learning. According to Meyer and Clark, “ Graphics should help the learner make sense of the material, otherwise it can disrupt the learning process.” (Clark, R. C., & Mayer, R. E., 2008). Extraneous graphics, even if they are interesting and indirectly connected to the information can easily distract from the concepts being taught. They can also create connections by the learner that are incorrect, or can simply just get in the way of the more pertinent material that needs to be processed and organized. Meyer and Clark’s research showed that learners who viewed a lesson without extraneous graphics produced 30% more correct answers than those who viewed a lesson with extraneous, but interesting graphics. In particular, according to Meyer and Clark’s research, “low ability students were more easily overloaded by the extraneous material.” (Clark, R. C., & Mayer, R. E., 2008) This is an important component, as any lesson should be designed to support learning for students of all ability levels.

Adding extraneous information in the form of words can also create cognitive processing overload in learners. This can be in the form of both written or narration. It is best to get straight to the point with relevant information and visuals. For example, in a presentation about film production steps, adding in a brief history of of the film camera might be interesting, but not directly connected to the true point of the presentation. It can also confuse students as to what they are expected to know for an assessment.

The Coherence Principle is a valuable tool in e-learning and multimedia presentation design. Staying focused on the specified learning outcomes and not muddying the waters by adding unneeded material seems fundamental to creating a scenario where students can learn most effectively. In my experience as a middle school teacher, there is a caveat to this principle. It is crucial to get students excited and engaged by the topics we teach from the start. When presenting a new unit of study, I have found that adding in some fun and extraneous material that can help students make real-world connections can be important to buy-in and motivation. When we get down to the more specific learning objectives and lessons, then the Coherence Principle really takes effect.

Clark, R. C., & Mayer, R. E. (2008). E-learning and the science of instruction, 2nd edition. Pfeiffer: San Francisco, CA.

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 March 23, 2012 from http://imej.wfu.edu/articles/2000/2/05/index.asp

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