Introduction and Overview. Theoretical Basis. Modeling Expertise. Modleing System: User Cooperation in KADS. A KADS Domain Description Language. Model Construction. Operationalizing Models of Expertise. KADS and Conventional Software Engineering. Languages and Tools. A Formal Language for KADS Models of Expertise. MODEL-K: Making KADS Run. Using OMOS to Represent KADS Conceptual Models. Shelley-Computer Aided Knowledge Engineering. Applications. The Paint Advisor: A Communicative Expert System. Managing and Maintaining an Operational KADS System. Rational Reconstruction of Diagnostic Expertise. Qualitative Prediction of Behavior. A KADS Conceptual Model of the ONOCIN Task. Applying KADS to the Sisyphus Domain. Using KADS to Analyze Problem-Solving Methods. Bibliography. Name Index. Subject Index.