Best Practices of Live Classes

Over the years I've heard serveral theories regarding the optimal length of a live online class.  Some believe it's 5-minutes while others think half-a-day, so needless to say there is no one truth out there.  This brings me to an interesting blog posting by Paul Lowe, a photography lecturer at the London College of Communication.  He explores this notion of ideal length and concludes that 2-3 hours is optimal for his online classes for grad students, as he says it's easier for them to schedule one long block of time per week than multiple shorter sessions.  Let the debate continue....