Theoretical Research: Results and Proposals -- The Complexity of Action Redundancy -- On the Impact of Small-World on Local Search -- A Hybrid Logic for Commonsense Spatial Reasoning -- Using a Theorem Prover for Reasoning on Constraint Problems -- Good and Bad Practices in Propositionalisation -- Periodicity-Based Temporal Constraints -- A Survey of Problem Difficulty in Genetic Programming -- Intelligent Information Access by Learning WordNet-Based User Profiles -- Refined Approximation of Concepts in Ontology -- Theoretical Research: Improvements and Consolidations -- Argumentation for Access Control -- Determining Preferences Through Argumentation -- Avoiding Order Effects in Incremental Learning -- Evaluating Search Strategies and Heuristics for Efficient Answer Set Programming -- The SCIFF Abductive Proof-Procedure -- Scheduling with Probability and Temporal Constraints -- Schedule Robustness Through Broader Solve and Robustify Search for Partial Order Schedules -- Optimal Scheduling with Heuristic Best First Search -- Planning with Derived Predicates Through Rule-Action Graphs and Local Search Techniques -- The Architecture of a Reactive Path-Planner for Mobile Robots Based on Cellular Automata -- Modal Operators with Adaptable Semantics for Multi-agent Systems -- An Organisation Infrastructure for Multi-agent Systems Based on Agent Coordination Contexts -- Towards Fault-Tolerant Formal Concept Analysis -- Agent-Based Management of Responsive Environments -- An ACL for Specifying Fault-Tolerant Protocols -- Experimental Evaluation of Hierarchical Hidden Markov Models -- Optimization of Association Rules Extraction Through Exploitation of Context Dependent Constraints -- Automata Slicing for Diagnosing Discrete-Event Systems with Partially Ordered Observations -- Configurations for Inference from Causal Statements: Preliminary Report -- Laying the Foundations for a Formal Theory of Drama -- A Semantic Kernel to Exploit Linguistic Knowledge -- Building a Wide Coverage Dynamic Grammar -- A Linguistic Inspection of Textual Entailment -- Multigranular Scale Speech Recognizers: Technological and Cognitive View -- Applications: Systems and Prototypes -- Towards a General Framework for Substitutional Adaptation in Case-Based Reasoning -- A Consumer Interest Prediction System from Transaction Behaviors in Electronic Commerce -- Dealing with Different Languages and Old Profiles in Keystroke Analysis of Free Text -- Learning Path Generation by Domain Ontology Transformation -- A Multidimensional Framework for the Representation of Ontologies in Adaptive Hypermedia Systems -- A Conversational Agent Based on a Conceptual Interpretation of a Data Driven Semantic Space -- Solving Italian Crosswords Using the Web -- A Counterfactual-Based Learning Algorithm for Description Logic -- Relational Learning: Statistical Approach Versus Logical Approach in Document Image Understanding -- Handling Continuous-Valued Attributes in Incremental First-Order Rules Learning -- Prototypal Ambient Intelligence Framework for Assessment of Food Quality and Safety -- Managing Clinical Guidelines Contextualization in the GLARE System -- Water Management Policy Selection Using a Decision Support System Based on a Multi-agent System -- A CSP Approach for Modeling the Hand Gestures of a Virtual Guitarist -- Experiences with CiceRobot, a Museum Guide Cognitive Robot -- Human-Robot Interaction Through Mixed-Initiative Planning for Rescue and Search Rovers -- Anchoring by Imitation Learning in Conceptual Spaces -- Bayesian Emotions: Developing an Interface for Robot/Human Communication -- Robot Security and Failure Detection Using Bayesian Fusion -- Applications: Case Studies and Proposals -- Mining Relational Association Rules for Propositional Classification -- Entity Recognizer in Hungarian Question Processing -- Recognition Algorithm for Korean Postpositions by Detecting Prosody Boundaries -- Fuzzy Multinomial Control Charts -- Fuzzy Logic Resource Manager: Fuzzy Rules and Experiments -- Application of PGA on Optimization of Distribution of Shopping Centers -- BIOPACMAS: A Personalized, Adaptive, and Cooperative MultiAgent System for Predicting Protein Secondary Structure -- Improving Neural Classification with Markov Chain -- Intelligent Neurofuzzy Model Based Control of Electrically Heated Micro Heat Exchanger -- Managing Functional and Ontological Knowledge in the Design of Complex Mechanical Objects.This volume collects the papers selected for presentation at the IX Congress of the Italian Association for Arti?cial Intelligence (AI*IA), held in Milan at the University of Milano–Bicocca (September 21–23, 2005). On the one hand this congress continues the tradition of AI*IA in organizing its biannual s- enti?c meeting from 1989; on the other hand, this edition is a landmark in the involvement of the international community of arti?cial intelligence (AI), directly involving a broad number of experts from several countries in the P- gramCommittee. Moreover,the peculiar nature of scienti?c researchin arti?cial intelligence (which is intrinsically international) and several consolidated int- national collaborations in projects and mobility programs allowed the collection and selection of papers from many di?erent countries, all around the world, enlarging the visibility of the Italian contribution within this research ?eld. Arti?cial intelligence is today a growing complex set of conceptual, theor- ical, methodological, and technological frameworks, o?ering innovative com- tational solutions in the design and development of computer-based systems. Within this perspective, researchers working in this area must tackle a broad range of knowledge about methods, results, and solutions coming from di?erent classical areas of this discipline. The congress was designed as a forum allowing researchers to present and discuss specialized results as general contributions to AI growth.