ELIZA, the first chatbot, published by Joseph Weizenbaum
Joseph Weizenbaum's ELIZA used simple pattern matching to simulate a Rogerian psychotherapist; people's emotional attachment to it gave rise to the term 'ELIZA effect'.
Key facts
- Described in Communications of the ACM, vol. 9, no. 1 (January 1966)
- Best-known script: DOCTOR (Rogerian psychotherapist)
- Worked by keyword matching and template-based reassembly
- Weizenbaum later became a critic of over-trusting computers
What happened
Weizenbaum published ELIZA, a program that produced conversational replies by rephrasing user input according to scripted rules.
Why it matters
The first chatbot, and the first vivid demonstration that humans readily anthropomorphize conversational software — a lesson that became central again with ChatGPT.
Changelog
- 2026-09-29: created
Related events
- OpenAI launches ChatGPT ★★★★★
Sources (2)
- paperELIZA—a computer program for the study of natural language communication (CACM, DOI)
- discussionWikipedia: ELIZA
id: 1966-01-01-eliza · updated 2026-09-29 · open in the interactive timeline