Visual Modeling for Complex Agent-Based Simulation Systems Candelaria Sansores, Juan Pavón and Jorge Gómez-Sanz * Universidad Complutense Madrid, Dep. Sistemas Informáticos y Programación 28040 Madrid, Spain csansores@fdi.ucm.es ,{jpavon, jjgomez}@sip.ucm.es Abstract. Currently there is a diversity of tools for agent-based simulation, which can be applied to the understanding of social phenomena. Describing this kind of phenomena with a visual language can facilitate the use of these tools by users who are not necessarily experts in computer programming, but in social sciences. With this purpose, we propose to define such visual language, which is based on well established concepts of agent-oriented software engineering, and more concretely on the INGENIAS methodology. The proposed language is independent of any particular simulation platform and, by using INGENIAS code generation support, it is possible to generate implementations for the desired target platforms. Also, we consider that modeling should be application domain oriented and that a generic language itself does not suffice. Thus, we discuss at the end how specific domain simulation environments could be achieved. 1 Motivation Agent-based modeling and simulation is being increasingly used for exploring the complexity of social dynamics. This approach facilitates the study of how social phenomena emerge, that is, how the interactions and varied behaviors of individual agents produce structures and patterns. Thus, agent based modeling is well suited for studying systems that are composed of interacting agents and exhibit properties arising from the interactions of the agents that cannot be deduced simply by aggregating the properties of the agents. This is the kind of problems that appear when studying complex adaptive systems like those found in social sciences. Complex adaptive systems are often characterized by agents interacting or capable of interacting with each other in dynamic, nonlinear and unpredictable ways [12]. From a computer science view, a complex adaptive system is a form of complex multi-agent system (MAS) with adaptive agents. However, complex MAS are rarely implemented because the system can become easily intractable. Thus, the general approach to study a complex adaptive system is a computer simulation, in which * This work has been developed with support of the Consejo Nacional de Ciencia y Tecnología (CONACYT) from México and the project TIC2002-04516-C03-03, funded by the Spanish Council for Science and Technology.