The management and processing of uncertain information has shown itself to be a crucial issue in the development of intelligent systems, beginning withits appearance in the such systems as Mycin and Prospector. The papers in this volume reflect the current range of interests or researchers in thefield. Currently, the major approaches to uncertainty include fuzzy set theory, probabilistic methods, mathematical theory of evidence, non-standardlogics such as default reasoning, and possibility theory. The initial part of the volume is devoted to papers dealing with the foundations of these approaches, where recent attempts have been made to develop systems combining multiple approaches. A significant part of the book looks at the management of uncertainty in a number of the paradigmatic domainsof intelligent systems such as expert systems, decision making, databases, image processing, and reasoning networks. The papers are extended versions of presentations at the third international conference on information processing and management of uncertainty in knowledge-based systems. The proceedings of the two preceding IPMU conferences appear as LNCS 286 and LNCS 313.