Diagnosing with Mycin (1972)
These notes are from John's slides. He has a much more thorough
Write down some diagnostic problems that RBSs could be used for.
Can you think of some diagnostic problems RBSs couldn't be used for?
- Purpose: to assist a physician, who was not an expert in the
field of antibiotics, with the diagnosis & treatment of blood
disorders (and in particular to establish whether the patient was
suffering from a serious infection like meningitis).
- Input: symptoms & test results
- Output: a diagnosis, accompanied by a degree of certainty, &
- Knowledge representation: production rules (and simpler data structures)
- Inference engine: Mixed chaining, but principally backward
chaining from a top goal: that diagnosis & therapy is needed. Rules
are found to satisfy conditions of this rule, then further rules to
satisfy these. Evidence may be sought from the user.
- A successful (and enormously influential) expert system:
- did a complex task.
performed well: tested against medical students, non-specialist doctors and blood infection specialists, it did better than the former two groups and equalled the latter group.
- but note that MYCIN was just a laboratory demonstration - it was never marketed, or installed in a hospital and used for routine work.