What does brainstorming, workshops with sticky notes, small online group learning and big distributed networks of researchers have in common? They are all grappling with big ideas, and trying to make sense of them. This talk identifies some common principles of idea-centric learning, and brings in examples from the learning sciences literature to discuss how the design of a collaborative platform can affect the direction and quality of the discourse that happens. Invited talk in CCK11, April 6, 2011. Extended notes: http://reganmian.net/wiki/grappling_with_ideas