This book describes a theory of memory representation, organization, and processingfor understanding complex narrative texts. The theory is implemented as a computer program calledBORIS which reads and answers questions about divorce, legal disputes, personal favors, and thelike. The system is unique in attempting to understand stories involving emotions and in being ableto deduce adages and morals, in addition to answering fact and event based questions about thenarratives it has read. BORIS also manages the interaction of many different knowledge sources suchas goals, plans, scripts, physical objects, settings, interpersonal relationships, social roles,emotional reactions, and empathetic responses.The book makes several original technicalcontributions as well. In particular, it develops a class of knowledge constructs called ThematicAbstraction Units (TAUs) which share similarities with other representational systems such asSchank's Thematic Organization Packets and Lehnert's Plot Units. TAUs allow BORIS to representsituations which are more abstract than those captured by scripts, plans, and goals. They containprocessing knowledge useful in dealing with the kinds of planning and expectation failures thatcharacters often experience in narratives; and, they often serve as episodic memory structures,organizing events which involve similar kinds of planning failures and divergent domains.An appendixcontains a detailed description of a demon-based parser, a kernel of the BORIS system, as well asthe actual LISP code of a microversion of this parser and a number of exercises for expanding itinto a full-fledged story-understander.Michael G. Dyer is an Assistant Professor in the Departmentof Computer Science at UCLA. His book is included in The MIT Press Artificial IntelligenceSeries.