The imitation game proposed by Turing originally included two phases. In
the first phase, shown in Figure 1.1, the interrogator, a man and a woman are
each placed in separate rooms and can communicate only via a neutral medium
such as a remote terminal. The interrogator’s objective is to work out who is the
man and who is the woman by questioning them. The rules of the game are
that the man should attempt to deceive the interrogator that he is the woman,
while the woman has to convince the interrogator that she is the woman.
In the second phase of the game, shown in Figure 1.2, the man is replaced by a
computer programmed to deceive the interrogator as the man did. It would even
be programmed to make mistakes and provide fuzzy answers in the way a human
would. If the computer can fool the interrogator as often as the man did, we may
say this computer has passed the intelligent behaviour test.
Physical simulation of a human is not important for intelligence. Hence, in
the Turing test the interrogator does not see, touch or hear the computer and is
therefore not influenced by its appearance or voice. However, the interrogator
is allowed to ask any questions, even provocative ones, in order to identify
the machine. The interrogator may, for example, ask both the human and the