A guide to the critical part of the knowledge-gathering process - eliciting human expertise for machine representation. This book details the process, models and techniques used by professionals actively involved in expert-system development in business and industry. This updated edition places greater emphasis on prototyping, user involvement and the need for rigorous testing and quality control techniques. A section on human issues has also been extended to include the most recent research. Topics covered include a comparison of systems analysis, the role of the knowledge engineer, reasoning and probability theory, fuzziness in reasoning and machine induction amongst others.