Interaction with Expert

Test cases often reveal missing pieces of knowledge. Experts cannot ``tell all they know'', but they quickly spot errors. When the expert spots an error, that leads to new rules.

Example: Fever of Unknown Origin

Patient is 17-year-old female; persistent fever, headache, lethargy, cardiac symptoms, ...

Diagnoses: Lung cancer (.81), Endocarditis (7).

Correct diagnosis was endocarditis. Physician expert said the diagnosis of lung cancer was consistent with the symptoms; however, lung cancer would never be expected in a patient this young.

Result: new rules added to rule out certain cancers in young patients. Patient age can be used to determine certainty factor of ruling out lung cancer.