In artificial intelligence ( AI ), the Turing Test is a method for determining whether or not a computer is capable of thinking like a human. The test is named after Alan Turing , an English mathematician who pioneered artificial intelligence during the 1940s and 1950s, and who is credited with devising the original version of the test. According to this kind of test, a computer is deemed to have artificial intelligence if it can mimic human responses under specific conditions. In Turing's test, if the human being conducting the test is unable to consistently determine whether an answer has been given by a computer or by another human being, then the computer is considered to have "passed" the test.
In the basic Turing Test, there are three terminal s. Two of the terminals are operated by humans, and the third terminal is operated by a computer. Each terminal is physically separated from the other two. One human is designated as the questioner. The other human and the computer are designated the respondents. The questioner interrogates both the human respondent and the computer according to a specified format, within a certain subject area and context, and for a preset length of time (such as 10 minutes). After the specified time, the questioner tries to decide which terminal is operated by the human respondent, and which teminal is operated by the computer. The test is repeated many times. If the questioner makes the correct determination in half of the test runs or less, the computer is considered to have artificial intelligence, because the questioner regards it as "just as human" as the human respondent.
The Turing Test has been criticized, in particular because the nature of the questioning must be limited in order for a computer to exhibit human-like intelligence. For example, a computer might score high when the questioner formulates the queries so they have "Yes" or "No" answers and pertain to a narrow field of knowledge, such as mathematical number theory. If response to questions of a broad-based, conversational nature, however, a computer would not be expected to perform like a human being. This is especially true if the subject is emotionally charged or socially sensitive.
In some specialized instances, a computer may perform so much better and faster than a human that the questioner can easily tell which is which. Google, Yahoo, and AltaVista are examples of computer applications that outperform a human in a Turing Test based on information searches.