Coherence Principle

Ryan Baker
Edtech 513
Coherence Principle

    While each teacher is in love with their subject matter, we did major in it after all, we must (reluctantly) admit that it's not always as exciting to our students as it is to us.  The natural inclination is to attempt to "jazz it up" and insert exciting, but possibly only tangentially related, content.  The Coherence Principle rejects that thinking and forces us to focus on the important aspects of the lesson instead.
    Our knee jerk inclination to insert exciting extras, referred to as seductive details, is understandable.  Arousal theory would seem to indicate that the interest generated by the exciting bits would carry over to the less exciting bits, thus assisting learning (Clark, 2008, p. 135).  Experiments, however, have found the exact opposite (Clark, 2008, p. 136).  The Coherence Principle explains why.
    The Coherence Principle is based in cognitive theory.  Cognitive theory holds that humans have only so much capacity for input at any one given time (this is the reason you turn down your car radio when driving in a strange neighborhood). Further, the extraneous information (included in a lesson to make it more interesting) demands a great deal of that limited capacity (Clark, 2008, p. 133).  Therefore, extraneous, tangentially related material detracts from learning rather than enhancing it. Students learn more deeply when they do not have to process extraneous words and sounds in verbal working memory (Mayer, 2002, p. 107). As Dewey said even after adding exciting extras the original information "is no more interesting than it was before" (Clark, 2008, p. 138).
    The Coherence Principle is in line with other educational principles such as the redundancy principle and the multimedia principle.  The redundancy principle reiterates the limits of our learning capacity by teaching us to avoid duplicating the same information via audio and text as it has the effect of reducing retention of both (Clark, 2008, p. 117).  Similarly the multimedia principle says that well designed text and graphics enhance learning, it emphasizes the focus on relevant text and graphics (not seductive details) (Clark, 2008, p. 53).
    I have seen the positive effects of following the coherence principle (and the negative effects of ignoring it) in my own life.  In the high school I student taught seniors were required to do a research project and presentation called their "senior project".  When evaluating student PowerPoint's, those that avoided flashy graphics, irrelevant music and ill-advised movies were much more effective than those who included some "flash" just because they could.  Further, when one of my own lectures went off the rails due to the distracting nature of a PowerPoint animation (I had red, white and blue stars spin in and out every time I changed a slide), I learned quickly that more is not better. When giving a multimedia explanation, it is better to use fewer elements than lots of extraneous words and pictures (Moreno, 2000, p. 120).
    Overall, I like the coherence principle.  It reminds us to edit and gives us a tangible reason to do so (and a guideline on what to weed out).  The authors emphasize that the studies were not in a long term learning environment and were not on any particular or technical subject matter - so that there may be some caveats to how the coherence principle works.  However, in my experience, even if the coherence principle could be bent occasionally the rule is still a good one.


References
Clark, R. C., & Mayer, R. E. (2008). E-learning and the science of instruction, 2nd edition. Pfeiffer: San Francisco, CA.
Mayer, R. E., & Moreno, R. (2002). Aids to computer-based multimedia learning. Department of Psychology, University of California, Santa Barbara, CA. 12, 107–119. 
Moreno, Roxana, &  Mayer, Richard E. (2000) Journal of Educational Psychology, Vol 92(1), 117-125.