5. The method of claim 4 wherein the question is a medical question for a patient and the cohort analysis mechanism processes the medical history of the patient and finds the cohorts from medical histories of other patients to predict an answer from the cohorts.
4. The method of claim 1 wherein the cohort analysis mechanism determines an answer to the question using evidence gathered from a set of cohorts where case attributes in the set of cohorts does not match exactly attributes of the person in the question.