Anyone involved in e-learning will know of the cognitive theory of multimedia learning, which draws together information processing model (dual coding), cognitive load theory (working memory), and the notion of active processing. You can read a little more of this in this (old) post.
Anyway, for most of us who don’t do full on e-learning, Mayer’s principles have value when we make things like videos or multimedia that we wish the students to interact with outside of their time with us. As such, Mayer’s principles, as reported in The Cambridge handbook of multimedia learning are well cited. Mayer has just published an update (HT to the wonderful new Twitter feed: https://twitter.com/CogSciLearning), and because I have nothing better to do than twiddle my thumbs for the summer (thank you Adonis), I made a graphic summarising the 12 principles he describes. Many seem obvious but that is probably no bad thing; as well as thinking about videos, there might be some lessons about PowerPointing here too. Click on the image to embiggen.