Source : Free On-Line Dictionary of Computing

Turing test
     
         A criterion proposed by {Alan
        Turing} in 1950 for deciding whether a computer is
        intelligent.  Turing called it "the Imitation Game" and
        offered it as a replacement for the question, "Can machines
        think?"
     
        A human holds a written conversation on any topic with an
        unseen correspondent (nowadays it might be by {electronic
        mail} or {chat}).  If the human believes he is talking to
        another human when he is really talking to a computer then the
        computer has passed the Turing test and is deemed to be
        intelligent.
     
        Turing predicted that within 50 years (by the year 2000)
        technological progress would produce computing machines with a
        capacity of 10**9 bits, and that with such machinery, a
        computer program would be able to fool the average questioner
        for 5 minutes about 70% of the time.
     
        The {Loebner Prize} is a competition to find a computer
        program which can pass an unrestricted Turing test.
     
        {Julia (http://fuzine.mt.cs.cmu.edu/mlm/julia.html)} is a
        program that attempts to pass the Turing test.
     
        See also {AI-complete}.
     
        (1995-01-04)