Nick Morgan at Forbes points us to a terrific TEDx Houston talk by Professor Brené Brown. As Morgan writes, "Audiences long for presenters to be real with them, and just have a conversation. Sure, they want a focused, smart conversation, not a rambling, pointless one like so many real conversations. But they want an authentic connection with their speakers, and the way to achieve that is with a conversation."
Morgan goes on to explain that many presenters fear a conversation with their audience. They want to control the situation. Professors suffer from this same desire for control. As a result, they sometimes shy away from interactive learning processes, because they are not sure how they will handle unexpected conversations and questions.
I encourage you to read Morgan's article and watch Professor Brown's terrific talk: