Donald Clark remains one of my favourite bloggers on e-learning. In this post he discusses Mayer & Clark's research-based principles for designing instructional content. Required reading for anyone who ever needs to tell anyone anything using multiple media.

Of course, in a learning context, such principles are only of value in putting together a few of the basic building blocks, they are not a model for creating a full learning experience. Following these principles and ignoring the overall learning assembly of which they should form a small part would be a very bad idea. But we all need to communicate content, no matter what our theoretical educational leanings might be.