Conversational computers have come a long way

PEOPLE HAVE been conversing with computers since the 1960s, when Joseph Weizenbaum of the Massachusetts Institute of Technology created a “chatbot” called Eliza. Eliza was designed as both an electronic parlour trick and as a gentle mockery of psychotherapists. Its chief conversational gambit was repeating its interlocutors’ statements back to them in the form of questions. Yet Weizenbaum was surprised to discover that some of Eliza’s human interlocutors began to treat it as if it truly understood what they were telling it.A great deal of progress has been made since Eliza’s day. Every modern smartphone ships with a built-in voice assistant. Big computing firms such as Amazon and Google sell “smart speakers”—digital helpmeets that users can ask to provide everything from weather forecasts to film trivia. At the annual meeting of the American Association for the Advancement of Science participants were treated to a discussion of the present state of the art—and to a demonstration of its limitations.