Turing Test

The Turing test is a behavioural approach to determining whether or not a system is intelligent. It was originally proposed by mathematician Alan Turing, one of the founding figures in computing. Turing argued in a 1950 paper that conversation was the key to judging intelligence. In the Turing test, a judge has conversations (via teletype) with two systems, one human, the other a machine. The conversations can be about anything, and proceed for a set period of time (e.g., an hour). If, at the end of this time, the judge cannot distinguish the machine from the human on the basis of the conversation, then Turing argued that we would have to say that the machine was intelligent.

There are a number of different views about the utility of the Turing test in cognitive science. Some researchers argue that it is the benchmark test of what Searle calls strong AI, and as a result is crucial to defining intelligence. Other researchers take the position that the Turing test is too weak to be useful in this way, because many different systems can generate correct behaviours for incorrect (i.e., unintelligent) reasons. Famous examples of this are Weizenbaum's ELIZA program and Colby's PARRY program. Indeed, the general acceptance of ELIZA as being "intelligent" so appalled Weizenbaum that he withdrew from mainstream AI research, which he attacked in his landmark 1976 book.


  1. Colby, K.M. et al. (1972) Artificial paranoia. Artificial Intelligence, 2, 1-26.
  2. Colby, K.M. et al. (1973) Turing-like undistinguishability tests for the validation of a computer simulation of paranoid processes. Artificial Intelligence, 3, 47-51.
  3. Turing, A.M. (1950). Computing machinery and intelligence. Mind, 59, 433-560.
  4. Weizenbaum, J. (1976). Computer power and human reason. San Francisco, CA: W.H. Freeman.
University of Alberta Cognitive Science Dictionary

Dave's Diary
The Weird Bunch