this book presents the refereed proceedings of the 4th congress of the italian association for artificial intelligence, ai*ia 95, held in florence, italy, in october 1995.the 31 revised full papers and the 12 short presentations contained in the volume were selected from a total of 101 submissions on the basis of a careful reviewing process. the papers are organized in sections on natural language processing, fuzzy systems, machine learning, knowledge representation, automated reasoning, cognitive models, robotics and planning, connectionist models, model-based reasoning, and distributed artificial intelligence.