well-known principles: give both visual and auditory channels something to do, and reinforce the message with both. "When a presenter uses bullet-point slides, they’re not using both pathways as effectively as they could. The audience member has to read the words on the slide and listen to the presenter at the same time, leading to overloading of the language areas whilst leaving the visual cortex with very little to do."

Martin Weller on six principles to keep in mind while designing networked instruction.
1. <embed> is the universal acid of the web – we should build around it.
2. Simple with reach trumps complex with small audience.
3. Sharing is a motivation to participation - so make it easy and rewarding to do.
4. Start simple and let others build on top
5. Providing limitations frames input (Cf twitter, 12seconds, etc)
6. Complexity resides in the network not the application