Richard Mayer and Ruth Clark are among the foremost researchers in the empirical testing of media and media mix hypotheses in online learning. Their e-Learning and the Science of Instruction (2003) covers seven design principles; multimedia, contiguity, modality, redundancy, coherence, personalisation, and practice opportunities. Clear explanations are given about the risks of ignoring these principles - with support from worked examples and case study challenges. It should be a compulsory text for online learning designers.
Media mix is not mind rich
Their precise studies have confirmed that our media mix (text, graphics, audio, animation, video) in online learning is often flawed, resulting in cognitive overload and dissonance.....