ELIZA, the first chatbot, published by Joseph Weizenbaum
Confirmed
Importance: major (4 of 5)The takeaway
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’.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- Major (4 of 5)
- Last verified
- 29 September 2026
Your AI and this story
- GPT-6 AstraIn its training data
- Claude Opus 5.5In its training data
- Gemini 4 HydrogenIn its training data
- Grok 4.7In its training data
It happened before the cutoffs of all four assistants, so it can be in their training data.
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.
Sources
2 sources from 2 sites. Numbers match the chips in the text.
2 sources: 1 primary, 1 reaction
Primary
Reactions
- Wikipedia: ELIZAen.wikipedia.org, discussion
Changes
- Filed