Nederlands'Can machines think?' Alan Turing proposes an imitation game
In the journal Mind, Alan Turing proposes replacing the question of whether machines can think with a test: can an interrogator using a teleprinter tell a machine from a human?
MANCHESTER, October 1950 - "I propose to consider the question, 'Can machines think?'" With that sentence Alan Turing begins his article Computing Machinery and Intelligence in the philosophical journal Mind. Turing (38) is deputy director of the computing laboratory at the University of Manchester. He actually finds the question itself too vague to answer, and therefore proposes a practical test.
The imitation game
The set-up works like this. An interrogator sits in a separate room and communicates through a teleprinter with two conversation partners he cannot see. By asking questions, he has to work out who is who. In Turing's version, a machine takes the place of one of the two. The question then becomes: does the interrogator get it wrong as often as when he is talking to two humans?
In this way, according to Turing, the discussion shifts from what happens inside a machine to what it can demonstrably do. Appearance, voice and body play no part in this set-up.
A prediction for the year 2000
Turing ventures a concrete prediction. In about fifty years, he says, computers with a memory of around a billion bits will play the game so well that an average interrogator will have at most a 70 per cent chance of guessing correctly after five minutes. He also expects that by then people will speak of thinking machines without being contradicted.
Nine objections answered
A large part of the article deals with nine objections to thinking machines. They range from religious arguments to the limits that Kurt Gödel set on mathematical systems, and the claim that machines have no consciousness. Turing also addresses Ada Lovelace's objection from 1843: that a machine cannot come up with anything by itself. His answer is that machines regularly surprise him.
Machines that learn
At the end, Turing proposes not to rebuild the mind of an adult, but that of a child. Such a 'child machine' would then have to be brought up, with reward and punishment. This makes programming intelligence partly a matter of upbringing.
Looking back from 2026
The imitation game became world-famous as the Turing test. The article is also regarded as one of the first serious treatises on machine learning. Turing died on 7 June 1954, at the age of 41.
