The coherence principle presented by Clark and Mayer instructs e-learning designers to avoid adding or including material that does not support the instructional goal (Clark & Mayer, 2016). The premise for this principle is that learners have a limited capacity for processing and that capacity should be reserved for material that is directly related to the instructional goals. Clark and Mayer examined whether this principle applies for words, graphics, and or sounds. They found that e-learning works best when extraneous words, graphics, and sounds are avoided.
Words, graphics, and audio come at a cost. There is a cost to produce these items. Including them requires additional data storage and transmission capabilities and can make the lesson slower to access. When learners are paid for time in a training seat or paying for that instructional time, extra content has a real cost. However, the cost that should make e-learning desires most committed to excluding extra material is that it takes away from a learner’s already limited processing capacity.
E-learning designers are often tempted to include stories, trivia, decorative or entertaining graphics, background music, and/or sound effects because these things make their e-learning activity more interesting. It’s based on the idea that if you can stimulate emotional interest, you can stimulate cognitive interest. (Clark & Mayer, 2016) This idea is great, if the emotional interest is focused on the relevant content. Adding interesting content that isn’t relevant can arouse emotional interest, but it’s not focused on the relevant content so it doesn’t contribute to improved learning.
One example of the desire to arouse that comes to mind quickly is the “Crash Course in US History” Series by Josh Green. Mr. Green does an excellent job of including interesting and relevant graphics. His videos are fun and interesting to watch. However, upon further analysis, it’s clear that not all of the graphics, words, and sound effects that he uses are directly related to the learning goals. I’ll talk specifically about US History Episode 1, but the whole series features a similar style. This lesson is titled “The Black Legend, Native Americans, and Spaniards”. Based on a review of the description, the learning goals would have to do with the earliest Spanish settlements in the new world and their interactions with Native Americans. One could argue that the first 45 seconds are an introduction to the whole US history series and therefore the image of the moon and the “America” graphic with music and Tippecanoe are related to that whole course introduction. Fair enough. From the start learners are presented with a series of images at a fast pace. They illustrate the words that are being spoken, but are not relevant to the learning goal. It takes a lot of processing to keep up with the images, and there’s not much point in making the effort because they are all illustrations of what these groups were not like. Also, I spent way too much cognitive energy trying to figure out what the weird creature was on the chalkboard behind the instructor’s head. And why is George Washington there, Mr. Green? This video is engaging, and I think students might prefer it to reading a textbook, but I am not sure that it is as helpful as it could be if Mr. Green were to eliminate some of the distractions.
A video that does a much better job of providing interesting graphics while ensuring that all of the graphics are directly related to the learning goal is this video from TedEd by Ben Labaree Jr. The learning goals are related to the Kansas-Nebraska act and the influence it had in events leading up to the Civil War. There are several moments throughout the video that the Mr. Labaree could have used to insert some entertaining graphic and audio in the style of John Green, however, he carefully designed each visual to support the learning goals. In John Green’s style, a mention of the Civil War is opportunity to flash a picture of cannons blazing or wounded on a battlefield. Mr. Labaree resisted that opportunity because such images don’t support the learning goal of understanding the impact of the Kansas Nebraska act. Thinking about cannons or battlefields is a distraction from thinking about the opinions of northern and southern senators. The graphics in this video are well designed but not distracting. Perhaps I’m biased because I like history, but I find the video is plenty interesting. At the end of the video it’s very easy for me to identify who and what the video was about.
I can think of several examples of ways the coherence principle is violated when instructors attempt to create and use e-learning materials. I have seen videos with background music for no instructional reason (Moreno & Mayer, 2000). In online text I have seen little boxes presented of random trivia or extra information that was irrelevant to the learning goals. (Lehman, Schraw, McCrudden & Hartley, 2007) I have seen instructors include decorative graphics in an attempt to make their simple presentation look more interesting, but research indicates that this is not helpful (Mayer, Heiser, & Lonn, 2001) Often the clip art available seems related but is not relevant, yet instructors use it because they feel pressured to have graphics and don’t have time to find or create something more relevant. I have seen instructions that included additional words to add technical depth beyond the learning objectives. While this might seem like a good idea, the additional information may distract the learner from achieving the learning goals. (Mayer & Jackson, 2005, Verkoeijen & Tabbers, 2009)
The coherence principle provides a constraint for the other principles of multimedia, contiguity, modality, and redundancy. The multimedia principle encourages designers to include graphics with words, and the coherence principle cautions that those graphics must be relevant to the learning goals. The contiguity principle encourages designers to design in such a way that learners encounter the words and pictures at the same time. The coherence principle cautions that those words and pictures won’t help if they are not related to the learning goals. Modality encourages designers to present words as audio narration with graphics. The coherence principle cautions that those words must still be relevant to learning goals. The redundancy principle encourages designers that they should usually refrain from putting words that learners are listening to on the screen. Without the coherence principle, designers might be tempted to take liberties with those words since they aren’t on the screen, but the coherence principle reminds them to keep those words in alignment with the learning goals.
The coherence principle is dependent on psychological theories and exposes a limit for the arousal theory. The coherence principle is depending upon cognitive theories which state that learners have a limited capacity for cognitive processing. The coherence principle seems to be in conflict with the arousal theory which states that learners learn better when they have greater emotional interest. (Clark & Mayer, 2016) However, the coherence principle does not contradict the arousal theory because it leaves room for emotional interest as long as that emotional interest is directly related to the learning goals. It’s only when the emotional interest is not focused on learning goals that learning is diminished.
In my opinion, the coherence principle is an important principle to consider, but I would argue that it may not be a law to apply in all situations at all times. Certainly it is a good principle to follow in most times for most learners. Clark and Mayer used the term “decorative graphics” frequently in their description of extraneous images. (Clark & Mayer, 2016) Often I have observed that educators attempt to insert decorative graphics as an attempt to make their work more visually appealing and cover up for a lack of understanding of graphics design principles. I believe educators should consider the value of white space, font choice, contrast, and the alignment of items on a page rather than using images to make up for those deficiencies.
I also believe that designing e-learning is quite different than providing classroom instruction. While it is not explicit in learning objectives in courses, classroom instructors contribute to the social and emotional education of students. Part of that includes sharing life lessons, updates on school and community events, and fostering appropriate relationships in the classroom. It may seem natural to include such things when an instructor is creating an e-learning activity, but I think instructors should focus e-learning development on only those elements which are directly related to learning goals. Those other goals can be met in other ways outside of a learning module.
I believe the coherence principle is difficult to follow when it is difficult to determine which elements are relevant and which are simply related. What seems relevant to one instructor may be merely related to another. Designers should collaborate with others when the line between relevant and related is difficult to identify.
In my opinion, there are more studies to be done in this area. I would like to know if this principle applies as strongly for learners with more prior knowledge. I would also like to know if it applies when the content does not require as much processing For example when a group of high school students needs to learn a few things that are rather simple, is it okay to include related material that is entertaining? Does this apply at all maturity levels? I’m also not quite sure how well this principle relates to ideas about social connectivism and the importance of helping learners feel connected within a class, especially in an online class. When an instructor shares personal stories that are designed to develop relationships, is that extraneous? Should that always be presented separate from the actual lessons?
Clark, R. C., & Mayer, R. E. (2016). E-learning and the science of instruction, 4th edition. Hoboken, NJ: John Wiley & Sons, Inc.
Lehman, S., Schraw, G., McCrudden, M.T., & Hartley, K. (2007). Processing and recall of seductive details in scientific text. Contemporary Educational Psychology, 32, 569-587. DOI: 10.1016/j.cedpsych.2006.07.002
Mayer, R.E., Heiser, J., & Lonn, S. (2001). Cognitive constraints on multimedia learning; When presenting more material results in less understanding. Journal of Educational Psychology, 93, 187-198. DOI: 10.1037//0022-06126.96.36.199
Mayer, R.E. & Jackson, J. (2005). The case for coherence in scientific explanations: Quantitative details can hurt qualitative understanding. Journal of Experimental Psychology: Applied, 11, 13-18. DOI: 10.1037/1076-898X.11.1.13
Moreno, R., & Mayer, R. E. (2000). A coherence effect in multimedia learning: The case for minimizing irrelevant sounds in the design of multimedia instructional messages. Journal of Educational Psychology, 92, 117-125. DOI: 10.1037//0022 0663.92.1 117
Verkeoijen, P., & Tabbers, H. (2009). When quantitative details impair qualitative understanding of multimedia lessons. Educational Psychology, 29, 269-278. DOI: 10.1080/01443410902795586