Risk, probability and how our brains are easily misled

Some interesting discussion at The World Science Festival's panel on Probability and Risk that is relevant to how we ask questions in prediction markets and how we might expect a "crowd" to respond given certain uses of language or preconceptions:

http://arstechnica.com/science/news/2011/06/risk-probability-and-how-our-brains-are-easily-misled.ars