Differences between an expert system and a conventional data system:
A DSS is a form of management information system, which is designed to assist management in making semi-structured and unstructured decisions. This implies that some decisions are automated and others require judgement. The decision maker will use computers to do structured tasks of decisions while the other is the rest is judgement. An example of these decisions is investment decisions where data from automated sources is required.
An expert system is a system that acts as an expert consultant to the user. They are able t offer knowledge to the user through the use of knowledge base e.g. an system that diagnoses diseases.