Wikimedia Commons, Public Domain. Author: Bilby, 25 March 2008.
To address the question of whether machines can show the kind of intelligence that humans possess, Alan Turing devised the following test. Participants A and B, a human and a machine, are kept in isolated rooms. They answer questions posed by participant C, who cannot see them. C's task is to determine which is the machine and which is the human, while A and B try to convince C of their humanity. If C cannot tell the difference in human intelligence level between A and B more than half the time, the machine is considered intelligent. So far, no computer has passed the test. (Unit: 9)