Knowledge Representation and Reasoning.- Bayesian Networks: The Parental Synergy and the Prior Convergence Error.- Constraints for Representing Transforming Entities in Bio-ontologies.- Common-Sense Rule Inference.- Hard QBF Encodings Made Easy: Dream or Reality?.- CONGAS: A COllaborative Ontology Development Framework Based on Named GrAphS.- Pstable Semantics for Logic Programs with Possibilistic Ordered Disjunction.- Reasoning about Typicality with Low Complexity Description Logics: The Logic .- A Prioritized “And” Aggregation Operator for Multidimensional Relevance Assessment.- Deriving Information from Sampling and Diving.- Optimal Decision Tree Synthesis for Efficient Neighborhood Computation.- Mathematical Symbol Indexing.- Machine Learning.- Local Kernel for Brains Classification in Schizophrenia.- Improvement of the Classifier Performance of a Pedestrian Detection System by Pixel-Based Data Fusion.- Plugging Taxonomic Similarity in First-Order Logic Horn Clauses Comparison.- Empirical Assessment of Two Strategies for Optimizing the Viterbi Algorithm.- Approximate Frequent Itemset Discovery from Data Stream.- Kernel-Based Learning for Domain-Specific Relation Extraction.- Automatic Cluster Selection Using Index Driven Search Strategy.- The Necessity of Machine Learning and Epistemology in the Development of Categorization Theories: A Case Study in Prototype-Exemplar Debate.- Evolutionary Computation.- A Lexicographic Encoding for Word Sense Disambiguation with Evolutionary Neural Networks.- Feature Membership Functions in Voronoi-Based Zoning.- Optimal Planning with ACO.- Navigation in Evolving Robots: Insight from Vertebrates.- Search.- Social Tagging for Personalized Web Search.- Partitioning Search Spaces of a Randomized Search.- Improving Plan Qualityin SAT-Based Planning.- A New Approach to Iterative Deepening Multiobjective A*.- High Performing Algorithms for MAP and Conditional Inference in Markov Logic.- Natural Language Processing.- A Robust Geometric Model for Argument Classification.- Probabilistic Ontology Learner in Semantic Turkey.- Semantic Annotation of Legal Modificatory Provisions.- Towards Extensible Textual Entailment Engines: The EDITS Package.- “Language Is the Skin of My Thought”: Integrating Wikipedia and AI to Support a Guillotine Player.- Analyzing Interactive QA Dialogues Using Logistic Regression Models.- Multi-agent Systems.- An Agent-Based Paradigm for Free-Hand Sketch Recognition.- Solving Integer Programming Problems by Using Artificial Bee Colony Algorithm.- Representing Excuses in Social Dependence Networks.- Application.- Statistical and Fuzzy Approaches for Atmospheric Boundary Layer Classification.- Learning Local Correspondences for Static Signature Verification.- ML Techniques for the Classification of Car-Following Maneuver.- An Asynchronous Cellular Automata-Based Adaptive Illumination Facility.- Relational Temporal Data Mining for Wireless Sensor Networks.- Ontology-Driven Co-clustering of Gene Expression Data.- Value-Driven Characters for Storytelling and Drama.- A Knowledge Management System Using Bayesian Networks.- Knowledge Discovery and Digital Cartography for the ALS (Linguistic Atlas of Sicily) Project.- Parameter Tuning of a Stochastic Biological Simulator by Metaheuristics.- Hypotheses about Typical General Human Strategic Behavior in a Concrete Case.- A Fuzzy Approach to Product Configuration on Standard Databases.- Classifying Human Body Acceleration Patterns Using a Hierarchical Temporal Memory.

This book constitutes the refereed proceedings of the 11th International Conference of the Italian Association for Artificial Intelligence, AI*IA 2009, held in Reggio Emilia, Italy, in December 2009. The 50 revised full papers presented together with 3 invited talks were carefully reviewed and selected from 83 submissions. The papers are organized in topical sections on knowledge representation and reasoning, machine learning, evolutionary computation, search, natural language processing, multi-agent systems and application.