Verifying and testing expert system conceptual models

The authors recommend a two-phase approach to validating expert systems: (1) to use verification tools and techniques to establish formally specifiable properties of the expert system, such as freedom from logical redundancy, inconsistency, and deficiency; and (2) to use evaluation techniques to identify critical areas of expert system functionality and to identify sets of test cases for those areas. A verification tool can then be used to establish whether the expert system functions correctly, according to these test cases. This approach is elucidated