ELIZA is a famous 1966 computer program by Joseph Weizenbaum, which parodied a Rogerian therapist, largely by rephrasing many of the patient's statements as questions and posing them to the patient. Thus, for example, the response to "My head hurts" might be "Why do you say your head hurts?" The response to "My mother hates me" might be "Who else in your family hates you?"

It is sometimes inaccurately said that ELIZA "simulates" (or worse, "emulates") a therapist. Weizenbaum said that ELIZA provided a "parody" of "the responses of a nondirectional psychotherapist in an initial psychiatric interview." He chose the context of psychotherapy to "sidestep the problem of giving the program a data base of real-world knowledge", the therapeutic situation being one of the few real human situations in which a human being can reply to a statement with a question that indicates very little specific knowledge of the topic under discussion. For example, it is a context in which the question "Who is your favorite composer?" can be answered acceptably with responses such as "What about your own favorite composer?" or "Does that question interest you?"

Eliza worked by simple pattern recognition and substitution of key words into canned phrases. It was so convincing, however, that there are many anecdotes about people becoming very emotionally caught up in dealing with ELIZA. All this was due to people's tendency to attach to words meanings which the computer never put there.

In assessing the impact of ELIZA, recall that in 1966 interactive computing (via a teletype) was new. It was a decade before the Colossal Cave adventure game spawned the interactive fiction genre; a decade and a half before the personal computer became familiar to the general public; and two decades before most people encountered attempts at natural language processing in Internet services like Ask Jeeves! or PC help systems such as Microsoft Office Clippy. Even today, ELIZA is amusing and capable of inducing suspension of disbelief. Its responses, while less useful than those of Ask Jeeves! or Clippy, often seem to demonstrate a deeper level of understanding. In 1966, ELIZA was staggering.

Lay responses to ELIZA were disturbing to Weizenbaum and motivated him to write his book Computer Power and Human Reason. From Judgment to Calculation, in which controversially he explains the limits of computers, as he wants to make clear in people's minds his opinion that the anthropomorphic views of computers are just a reduction of the human being and any lifeform for that matter.

ELIZA was named after Eliza Doolittle, the working-class character in Shaw's Pygmalion who is taught to speak with an upper class accent.

Implementations

• Very advanced DOS-based version: http://ecceliza.cjb.net
• Using JavaScript: http://www.manifestation.com/neurotoys/eliza.php3
• Source code in Java: http://chayden.net/eliza/Eliza.shtml
• Using C on the TI-89: http://kaikostack.com/ti89_en.htm#eliza
• A perl module Chatbot::Eliza -- example implementation, usage tutorial
• AOLiza was an ELIZA-like AI which runs over the AIM protocol.
• An edited version called Azile (Eliza backwards) says rude insults instead of the psychologist responses
• A version of ELIZA, called "Doctor" is included with the popular Emacs editor.

See also

• ELIZA effect
• A.L.I.C.E.
• PARRY
• Turing test
• Loebner prize
• Simulated consciousness
• Chatterbot

References

External links

• dialogues with colorful personalities of early AI, a collection of dialogues between ELIZA and various conversants, such as a company vice president and PARRY (a simulation of a paranoid schizophrenic)
• AOLiza
• EllaZ Systems has on-line chatbots that extend the potential of ELIZA to interactive games and Convuns (conversational units). Functional features utilize Web Services, WordNet, CIA World Fact Book, and other resources. All with natural language interaction.