Superforecasting: The Art and Science of Prediction

by Philip E. Tetlock

“Doubt is not a fearful thing,” Feynman observed, “but a thing of very great value.”10 It’s what propels science forward.

Scientists must be able to answer the question “What would convince me I am wrong?” If they can’t, it’s a sign they have grown too attached to their beliefs.

Researchers have found that merely asking people to assume their initial judgment is wrong, to seriously consider why that might be, and then make another judgment, produces a second estimate which, when combined with the first, improves accuracy almost as much as getting a second estimate from another person.

For superforecasters, beliefs are hypotheses to be tested, not treasures to be guarded.

Churchill sent Keynes a cable reading, ‘Am coming around to your point of view.’ His Lordship replied, ‘Sorry to hear it. Have started to change my mind.’7