Atlas record: https://www.aitimeline.dev/en/events/evt-0126/
Research · October 1974
MYCIN
The system advised on antibiotics for blood infections, held a dialogue with the physician, explained every step and attached a measure of confidence to its conclusion.
Why it matters
An expert system first acquired the three things it cannot be used without: explanation, handling of uncertainty, and rules kept separate from the mechanism.
About 200 if-then rules in the first full description of the system (an article received in June 1974), each with a certainty factor; by 1978 the book's editors count almost 500. The physician could ask why a question was being asked and get the chain of reasoning back. The inference engine was separated from the rule base and turned into EMYCIN, an empty shell reusable in other domains. MYCIN never entered clinical practice, partly over questions of liability, partly because it needed a terminal and a consultation that took 15 to 20 minutes and about 45 questions.
Event record
- Event date
- October 1974
- Timeline date
- Event date
- Verification
- Sources gathered automatically · September 17, 2026
- Lines
- ID
- evt-0126
The thesis was defended at Stanford in October 1974; the book form appeared in 1976 from American Elsevier. The record anchors on the work, not the book.
Sources
- primary Computer-Based Medical Consultations: MYCIN
American Elsevier · Published 1976
- primary E. H. Shortliffe, R. Davis, S. G. Axline, B. G. Buchanan, C. C. Green, S. N. Cohen, Computer-Based Consultations in Clinical Therapeutics: Explanation and Rule Acquisition Capabilities of the MYCIN System, Computers and Biomedical Research 8, 1975, pp. 303-320
Academic Press (scan hosted by the Federal University of Parana) · Published 1975
- primary E. H. Shortliffe, Details of the Consultation System (chapter 5), in B. G. Buchanan, E. H. Shortliffe (eds.), Rule-Based Expert Systems: The MYCIN Experiments of the Stanford Heuristic Programming Project, Addison-Wesley, 1984, pp. 78-132
Addison-Wesley (author-hosted copy at shortliffe.net) · Published 1984
Related events
Earlier
- Builds on The DENDRAL project begins 1965
The system was built by the same people on the same domain-knowledge principle as DENDRAL.
- Builds on Lisp 1960
The system is written in Lisp.
- Related Ledley and Lusted: logic and probability of diagnosis 1959links to this record
Both records concern a machine advising a physician on diagnosis: in 1959 as a mathematical formulation with probability and value theory, in 1974 as a program with rules and certainty factors. The 1975 MYCIN paper read does not cite Ledley and Lusted.
Later