Progress in artificial intelligence has long been measured by its mastery of board games like chess, backgammon, and Go. Researchers are now working on poker and computer games such as Starcraft. Iyad Rahwan, a professor at MIT, respects those milestones but says the focus on beating humans in direct competition has led us to neglect other ways of measuring and advancing AI. He argues that as smart machines look set to become pervasive, more effort should be devoted to creating software that learns to coöperate with humans. "This is the next important problem, because AIs don't always have to replace us, they have to live with us," says Rahwan.