{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/1966-01-01-eliza/","md":"https://postcutoff.com/e/1966-01-01-eliza/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"1966-01-01-eliza","date":"1966-01-01","date_precision":"month","short_title":"ELIZA, the first chatbot, published by Joseph Weizenbaum","deck":null,"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'.","category":"research","category_label":"Research","importance":4,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"ELIZA—a computer program for the study of natural language communication (CACM, DOI)","url":"https://doi.org/10.1145/365153.365168","type":"paper","group":"primary","domain":"doi.org"},{"n":2,"title":"Wikipedia: ELIZA","url":"https://en.wikipedia.org/wiki/ELIZA","type":"discussion","group":"reactions","domain":"en.wikipedia.org"}],"official":1,"filed":"2026-09-29","updated":"2026-09-29","orgs":["MIT"],"title":"ELIZA, the first chatbot, published by Joseph Weizenbaum","summary":"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"],"key_numbers":[],"tags":["chatbot","nlp","history"],"science":null,"body_md":"## What happened\n\nWeizenbaum published ELIZA, a program that produced conversational replies by rephrasing user input according to scripted rules.\n\n## Why it matters\n\nThe first chatbot, and the first vivid demonstration that humans readily anthropomorphize conversational software — a lesson that became central again with ChatGPT.","disputed":[],"related":[{"id":"2022-11-30-chatgpt","url":"https://postcutoff.com/e/2022-11-30-chatgpt/","date":"2022-11-30","date_precision":"day","short_title":"OpenAI launches ChatGPT","deck":null,"takeaway":"The moment AI became a mass-market technology — the start of the current era of AI investment, adoption and policy attention.","category":"product","category_label":"Products","importance":5,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":2,"official":1,"filed":"2026-09-29","updated":"2026-09-29","orgs":["OpenAI"]}],"people":[],"posts":[],"videos":[],"models":[],"changes":[{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-29","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":null,"in_training_data":true},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":null,"in_training_data":true},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":null,"in_training_data":true},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":null,"in_training_data":true}],"short_url":"https://postcutoff.com/s/eliza-first-chatbot-joseph"}