e-Learning and the Science of Instruction: Proven Guidelines for Consumers and Designers of Multimedia Learning

7.12. What We Don't Know About Coherence

As you can see in this chapter, there is strong and consistent support for the coherence effect. In the latest review, Mayer (in press) listed positive results for eliminating extraneous materials in thirteen out of fourteen experiments, with a median effect size near 1. In spite of this initial body of useful research evidence, there is still much we do not know about the coherence principle. Much of the research reported in this chapter deals with short lessons delivered in a controlled lab environment. Does the coherence effect also apply to longer-term instruction presented in an authentic learning environment, such as a training program? It would be useful to determine whether students can learn ...