It’s only natural to seek certainty, especially in the face of the unknown. Long ago, shamans performed intricate dances to summon rain. It didn’t matter that any success they enjoyed was random, as long as the tribe felt that its water supply was in capable hands. Nowadays, late nights of number crunching, feasts of modeling, and the familiar rituals of presentations have replaced the rain dances of old. But often, the odds of generating reliable insights are not much better.