Philip Tetlock is Leonore Annenberg University Professor of Psychology at the University of Pennsylvania. He is the author of several books on politics and psychology, including Counterfactual Thought Experiments in World Politics and the award-winning Expert Political Judgment: How Good Is It? How Can We Know? Dan Gardner is a journalist, author and lecturer. He is the best-selling author of Future Babble:__Why Expert Predictions Fail and Why We Believe them Anyway and Risk: The Science and Politics of Fear , which was published in 11 countries and 7 languages. He lives in Ottawa, Canada.