Alan M. Turing, considered by many to be the founder of computer science, proposed a test as a means of determining whether a machine is intelligent or not, with behavior as a criterion for intelligence. In the Turing Test, a human judge engages in a casual conversation with other two individuals: one would be a human, and the other, a machine. They all are situated in different rooms for the sake of fairness, and the medium of communication is neutral. If the machines responses to arbitrary statements and questions are such that it cannot be reliably distinguished from the human, then the conclusion from the Turing Test is that the machine is intelligent. The Turing Test has been accepted by many A.I. researchers as the basis of success for A.I. innovation. A philanthropist by the name of Hugh Loebner has offered $100,000 to anyone who manages to pass it. However, this test has also raised many criticisms and issues that remain unresolved until today, with the test being only one attempt at defining ‘intelligence’ in machines. The basis of these criticisms lie on the fact that the test ignores what is actually happening inside the machine and focuses rather on a single aspect of a machine’s behavior.

A Conversation with ELIZA
ELIZA is a program written by Joseph Weizenbaum in the mid-90s, which emulates the responses of a psychiatrist during consultation by a patient. The following text would be a session taken from Weizenbaum’s original paper as an illustration. This can also be found in Goldschlager and Lister’s book.

Patient: Men are all alike.
ELIZA: In what way?
Patient: They’re always bugging us about something or another.
ELIZA: Can you think of a specific example?
Patient: Well, my boyfriend made me come here.
ELIZA: Your boyfriend made you come here.
Patient: He says I’m depressed most of the time.
ELIZA: I’m sorry to hear you are depressed.
Patient: It’s true, I am unhappy.
ELIZA: Do you think coming here will help you not to be unhappy?
Patient: I need some help, that much seems certain.
ELIZA: What would it mean to you if you got some help?
Patient: Perhaps I could learn to get along with my mother.
ELIZA: Tell me more about your family.
Patient: My mother takes care of me.
ELIZA: Who else in your family takes care of you?
Patient: My father.
ELIZA: Your father?
Patient: You are like my father in some ways.
ELIZA: What resemblance do you see?
Patient: You are not very aggressive, but I think you don’t want me to notice that.
ELIZA: What makes you think that I am not very aggressive?
Patient: You don’t argue with me.
ELIZA: Why do you think I don’t argue with you?
Patient: You are afraid of me.
ELIZA: Does it please you to believe I am afraid of you?
Patient: My father is afraid of everybody.
ELIZA: What else comes to your mind when you think of your father?
Patient: Bullies.
ELIZA: Does that have anything to do with the fact that your boyfriend made you come here?

From this example, it is obvious that ELIZA’s behavior is rather difficult to distinguish from that of human practitioners, and that the program, as said by Lister, satisfies the Turing test within a limited domain of conversation.