Includes bibliographical references and index.

This book constitutes the refereed proceedings of the 9th Congress of the Italian Association for Artificial Intelligence, AI-IA 2005, held in Milan, Italy in September 2005. The 46 revised full papers presented together with 16 revised short papers, were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on either theoretical research, with results and proposals, improvements and consolidations, or on applications as there are systems and prototypes, case studies and proposals. Within this classification, some of the main classical topics of AI are presented (agents, knowledge representation, machine learning, planning, robotics, natural language, etc.), but here the focus is on the ability of AI computational approaches to face challenging problems and to propose innovative solutions.