In recent years, social and organizational aspects of agency have become - jor research topics in MAS. Current applications of MAS in Web services, grid computing and ubiquitous computing highlight the need for using these aspects in order to ensure social order within such environments. Openness, hete- geneity, and scalability of MAS, in turn, put new demands on traditional MAS interaction models and bring forward the need to investigate the environment wherein agents interact, more speci?cally to design di?erent ways of constra- ing or regulating agents interactions. Consequently, the view...

This book constitutes the refereed proceedings of the 12th International Workshop on Multi-Agent-Based Simulation, MABS 2011, held in Taipei, Taiwan, in May 2011. The 10 revised selected and extended papers presented were carefully reviewed and selected from 21 submissions. The topics covered are MABS in scientometrics; MABS in politics, transit and policy; pedestrian, crowds and large scale MABS; and MABS modeling.

This book constitutes the thoroughly reviewed post-proceeding of International Workshops on Coordination, Organization, Institutions and Norms in Agent Systems, COIN@AAMAS 2012, held in Valencia, Spain in June 2012. The 13 revised full papers presented together with 1 invited talk went through several rounds of reviewing and revision and were carefully selected for presentations. The papers are organized in topical sections on compliance and enforcement, norm emergence and social strategies, refinement, contextualisation and adaptation.