PARRY is, besides ELIZA, the other famous early chatterbot. PARRY was written in 1972 by psychiatrist Kenneth Colby, then at Stanford University. While ELIZA was a tongue-in-cheek simulation of a Rogerian therapist, PARRY attempted to simulate a paranoid schizophrenic. The program implemented a crude model of the behavior of a paranoid schizophrenic based on concepts, conceptualizations, and beliefs (judgements about conceptualizations: accept, reject, neutral). It also embodied a conversational strategy, and as such was a much more serious and advanced program than ELIZA.

PARRY and ELIZA (also known as "the Doctor") "met" several times. The most famous of these exchanges occurred at the ICCC 1972, where PARRY and ELIZA were hooked up over ARPANET and "talked" to each other.

External links

• Parry's Source Code The original LISP code for Parry.
• RFC439 - Parry Encounters the Doctor Transcript of a session between Parry and Eliza. (This is not the dialogue from the ICCC, which took place October 24-26, 1972, whereas this session is from September 18, 1972.)