The Turing test—from every angle

Abstract

Can machines think? Turing’s famous test is one way of determining the answer. On the sixtieth anniversary of his death, the University of Reading announced that a ‘historic milestone in artificial intelligence’ had been reached at the Royal Society: a computer program had passed the ‘iconic’ Turing test. According to an organizer, this was ‘one of the most exciting’ advances in human understanding. In a frenzy of worldwide publicity, the news was described as a ‘breakthrough’ showing that ‘robot overlords creep closer to assuming control’ of human beings. Yet after only a single day it was claimed that ‘almost everything about the story is bogus’: it was ‘nonsense, complete nonsense’ to say that the Turing test had been passed. The program concerned ‘actually got an F’ on the test. The backlash spread to the test itself; critics said that the ‘whole concept of the Turing Test is kind of a joke . . . a needless distraction’. So, what is the Turing test—and why does it matter? In 1948, in a report entitled ‘Intelligent machinery’, Turing described a ‘little experiment’ that, he said, was ‘a rather idealized form of an experiment I have actually done’. It involved three subjects, all chess players. Player A plays chess as he/she normally would, while player B is proxy for a computer program, following a written set of rules and working out what to do using pencil and paper—this ‘paper machine’ was the only sort of programmable computer freely available in 1948 (see Ch. 31). Both of these players are hidden from the third player, C. Turing said, ‘Two rooms are used with some arrangement for communicating moves, and a game is played between C and either A or the paper machine’. How did the experiment fare? According to Turing, ‘C may find it quite difficult to tell which he is playing’. This is the first version of what has come to be known as ‘Turing’s imitation game’ or the ‘Turing test’.