Using synchronous chat for discussions may be an effective approach to student engagemen.

I have never thought of how to integrate a guest lecturer in an asynchronous online class.  This is an intriguing idea.  I guess this would primarily be accomplished by having the guest lecturer post a video lecture and then being invited to interact with atudens in the discussion board.  Something to consider.

I have been teaching online for more than 15 years, sooo I didn't actually learn anything new, but I do agree with all I've read this far.  I have designed, built, and taught many online classes in multiple disciplines so I've already learned by experience and have put these principles into practice.