Trust: Theory and Application -- Teammate Selection Using Multi-dimensional Trust and Attitude Models -- Noise Detection in Agent Reputation Models Using IMM Filtering -- Towards Improved Partner Selection Using Recommendations and Trust -- Generalizing Trust: Inferencing Trustworthiness from Categories -- Action-Based Environment Modeling for Maintaining Trust -- Combining Cognitive with Computational Trust Reasoning -- Welfare States and Social Trust: 'Crowding-Out' Dilemma -- A Trust-Based Incentive Mechanism for E-Marketplaces -- An Agent-Based Trust Model for Service-Oriented Systems -- Trust: Formal Models -- Agents Selecting Trustworthy Recommendations in Mobile Virtual Communities -- From Binary Trust to Graded Trust in Information Sources: A Logical Perspective -- Reputation Models -- Using the RePart Simulator to Analyze Different Reputation-Based Partnership Formation Strategies within a Marketplace Scenario -- Art Competition: Agent Designs to Handle Negotiation Challenges -- Towards Reputation Enhanced Electronic Negotiations for Service Oriented Computing -- SOARI: A Service Oriented Architecture to Support Agent Reputation Models Interoperability -- Reputation and Uncertainty Reduction: Simulating Partner Selection -- Experimental Evaluation of Deceptive Information Filtering in Context-Aware Service Selection.

This book constitutes the thoroughly refereed post-workshop proceedings of the 11th International Workshop on Trust in Agent Societies, TRUST 2008, held in Estoril, Portugal, in the context of AAMAS 2008, the main international conference on autonomous agents and multi-agent systems. The 17 revised full papers presented were carefully reviewed and selected from numerous submissions; they are fully revised to incorporate reviewers' comments and discussions at the workshop. The volume is organized in ternary topical sections on theoretical and applicative aspects of trust (from a engineering, cognitive, computational, sociological point of view), on formal models in the field of applied logic and applied mathematics, and finally on models of reputation systems, theory-driven and empirically backed-up guidelines for designing reputation technologies, and analysis and discussion of existing reputation systems.