In “Computing Machinery and Intelligence,” published in 1950 in the journal Mind, Alan Turing set aside the question “Can machines think?” in favor of his imitation game, in which a judge tries by text conversation to tell a human from a machine. He made a concrete forecast: that by around the year 2000, machines would play the game well enough to fool an average judge for about five minutes. The prediction was roughly the timescale on which chatbots first began passing short versions of the test.