Abstract:A case study‐based approach was used to develop the knowledge base of an expert system for marketing media class selection. Cases, in the context of business learning, are detailed, written descriptions of business problems and their resolution. An expert system rule set was developed for media class selection using standardised business case studies. The system developed was validated using another set of case studies. Using case studies has two knowledge elicitation advantages: (1) the knowledge source is standardised and relatively unambiguous and (2) less domain expert involvement is require