IF the subject's diagnosis is schizophrenia AND the subject has abnormal motor movement or posture AND the subject has inappropriate affect THEN the diagnosis is schizophrenia catatonic type. 3.3 Handling Uncertainties in Data. Since we will be using fuzzy systems theory, it is possible to qualify all data with the confidence that the data are in fact true. In particular, any data modified or created by the consequent will have that confidence attached. For the domain expert, writing the rules in English is a very good idea.
Diagnosis is a data element, holding a fuzzy set name dx with several members.
The rule requires that member dx of fuzzy set Diagnosis is schizophrenia, and that fuzzy facts has abnormal motor movement or posture and has inappropriate affect have non-zero confidence. Rules permit conditional gathering of additional data, since the consequent actions may include both writing text to the computer screen and reading values for data. For example, suppose that rule block 10 includes an in-depth exploration of parental relations. If this psychiatric expert system had a deeper purpose than simple screening, such a rule block would undoubtedly be included. The flexibility offered by the rule paradigm for formalizing thinking is very great.