Probability of Validity (the probability that a group’s decision is correct, as determined by majority vote)

This calculation of the probability of correctness—also known as Condorcet’s Jury Theorem—appears in Yuto Ichikawa’s novel *The Closed Room of God and the Ripples*.If p > 0.5, the group’s probability of getting the correct answer exceeds that of an individual (approaching “God’s answer”); if p < 0.5, it falls below it. Of course, each individual must answer completely independently.