Combining the strengths of human cognition and computer power, this book presents a practical application of artificial intelligence to the problem of retrieving information and facts with high-quality measures of precision and recall. It describes the System for Heuristic Retrieval of Information and Facts (SHRIF), a powerful and versatile system that is designed to exploit the lessons provided by humans who are able to attain partial, conflicting, and fuzzy goals effectively, despite limitations in speed and precision. In addition to information retrieval, SHRIF can serve as a model for any system with a variety of information processing objectives, from diagnosis and troubleshooting to classification and causal reasoning.