Dave Pollard writes:
There is a reason why people like conferences with a lot of unscheduled time between sessions, and why the hallway discussions are frequently more animated than the discussions in the conference rooms. Some people believe it’s because the quality of speakers is inadequate (specifically because they lack the ability to make complex, important subjects understandable and interesting), but I’m inclined to believe it’s more because most people get more value out of one-on-one and small-group conversations with both peers and experts, where they get to discuss the issues and get answers in the context of their particular situation. This is the same reason that students often get much more value out of personal coaching than they do from listening to lectures.
At one extreme, Unconferences can be totally unscheduled meetups, with no set topics (just an umbrella theme), self-organized in real time using Open Space or some similar technique. You spend the time talking about the issues you want to talk about with others who want to talk about the same issues. Everyone is an equal participant, and everyone needs to take the responsibility to prepare for the sessions by pre-reading and thinking in advance about the subjects.