A Pragmatic Reading of Friedman's Methodological Essay and What It Tells Us for the Discussion of ABMs

The issues of empirical calibration of parameter values and functional relationships describing the interactions between the various actors plays an important role in agent based modelling. Agent-based models range from purely theoretical exercises focussing on the patterns in the dynamics of interactions processes to modelling frameworks which are oriented closely at the replication of empirical cases. ABMs are classified in terms of their generality and their use of empirical data. In the literature the recommendation can be found to aim at maximizing both criteria by building so-called 'abductive models'. This is almost the direct opposite of Milton Friedman's famous and provocative methodological credo 'the more significant a theory, the more unrealistic the assumptions'. Most methodologists and philosophers of science have harshly criticised Friedman's essay as inconsistent, wrong and misleading. By presenting arguments for a pragmatic reinterpretation of Friedman's essay, we will show why most of the philosophical critique misses the point. We claim that good simulations have to rely on assumptions, which are adequate for the purpose in hand and those are not necessarily the descriptively accurate ones.Methodology, Agent-Based Modelling, Assumptions, Calibration

Artificial Science – a simulation test-bed for studying the social processes of science

it is likely that there are many different social processes occurring in different parts of science and at different times, and that these processes will impact upon the nature, quality and quantity of the knowledge that is produced in a multitude of ways and to different extents. It seems clear to me that sometimes the social processes act to increase the reliability of knowledge (such as when there is a tradition of independently reproducing experiments) but sometimes does the opposite (when a closed clique act to perpetuate itself by reducing opportunity for criticism). Simulation can perform a valuable role here by providing and refining possible linkages between the kinds of social processes and its results in terms of knowledge. Earlier simulations of this sort include Gilbert et al. in [10]. The simulation described herein aims to progress this work with a more structural and descriptive approach, that relates what is done by individuals and journals and what collectively results in terms of the overall process

Challenges in Modelling Social Conflicts: Grappling with Polysemy

This discussion paper originates from the preceding annual workshop of the Special Interest Group on Social Conflict and Social Simulation (SIG-SCSS) of the ESSA. The workshop especially focused on the need to identify and examine challenges to modeling social conflicts. It turned out that the polysemous nature of social conflicts makes it very difficult to get a grasp of their complexity. In order to deal with this complexity, various dimensions have to be taken into consideration, beginning with the question of how to identify a conflict in the first place. Other dimensions include the relation of conflict and rationality and how to include non-rational factors into conflict models. This involves a conception of organized action. Finally, guiding principles for model development are being discussed. We would like to invite readers of the Journal of Artificial Societies and Social Simulation to 'sow the seeds' of this debate.Social Conflicts, Conflict Models, Modelling Challenges, Polysemy, Rationality, Emotions

Developing a model of evacuation after an earthquake in Lebanon

This article describes the development of an agent-based model (AMEL, Agent-based Model for Earthquake evacuation in Lebanon) that aims at simulating the movement of pedestrians shortly after an earthquake. The GAMA platform was chosen to implement the model. AMEL is applied to a real case study, a district of the city of Beirut, Lebanon, which potentially could be stricken by a M7 earthquake. The objective of the model is to reproduce real life mobility behaviours that have been gathered through a survey in Beirut and to test different future scenarios, which may help the local authorities to target information campaigns.Comment: 8 pages, 11 figures, ISCRAM Vietnam Conference, November 201

If others jump to the queue front, how long I will wait?

Two models of a queue are proposed: a human queue and two lines of vehicles before a narrowing. In both models, a queuer tries to evaluate his waiting time, taking into account the delay caused by intruders who jump to the queue front. As the collected statistics of such events is very limited, the evaluation can give very long times. The results provide an example, when direct observations should be supplemented by an inference from the context.Comment: 4 pages, 3 figure

Challenges in modelling social conflicts: grappling with polysemy

International audienceThis discussion paper originates from the preceding annual workshop of the Special Interest Group on Social Conflict and Social Simulation (SIG-SCSS) of the ESSA. The workshop especially focused on the need to identify and examine challenges to modeling social conflicts. It turned out that the polysemous nature of social conflicts makes it very difficult to get a grasp of their complexity. In order to deal with this complexity, various dimensions have to be taken into consideration, beginning with the question of how to identify a conflict in the first place. Other dimensions include the relation of conflict and rationality and how to include non-rational factors into conflict models. This involves a conception of organized action. Finally, guiding principles for model development are being discussed. We would like to invite readers of the Journal of Artificial Societies and Social Simulation to 'sow the seeds' of this debate

Apports des rôles à la construction et à l'expérimentation de modèles multi-agents pour la gestion de ressources renouvelables

Le formalisme Agent-Groupe-Rôle propose de recourir à des abstractions organisationnelles (groupes et rôles) pour concevoir des systèmes multi-agents (SMA) selon une approche sociale, ou organisation centrée. Plutôt que de se concentrer sur les activités des agents, le concepteur d'un système AGR se concentre sur la structuration de ces activités. Dans le champ de la gestion de ressources renouvelables, les modélisateurs doivent apréhender des systèmes complexes où des dynamiques sociales et physiques se déroulent dans différents niveaux d'organisation entrelacés. Le formalisme AGR permet de représenter explicitement ces niveaux d'organisation et leurs articulations. Cette communication se concentre sur l'apport des rôles à la modélisation multi-agent pour la gestion de ressources renouvelables. Après avoir discuté du concept de rôle en informatique, les différents types de rôles introduits dans le modèle AGR d'une application de gestion d'étiage dans la vallée de la Drôme sont décrits. La question de la composition des rôles et la manière dont elle est résolué dans le cas de la Drôme sera examiné. Sur la base de cet exemple, un bilan des apports et limites de l'utilisation des rôles en termes d'expressivité et de modularité des modèles est dressé en conclusion / The Agent-Group-Role-Formalism has been introduced in the field of computer science as a possible instantiation of an organization-centred approach of multi-agent systems (MAS). Using groups and roles in MAS design, the AGR formalism brings the focus from agents activities description to agents activities structuring. In the field of agent-based modelling (ABM) for renewable resources management, modellers are facing complex systems where social and physical dynamics take place within various interwoven levels of organization. Using AGR formalism is a way to explicitly represent the various levels of organization of a system and their articulations. This paper focuses on the use of roles in ABM for renewable resources management. The concept of role in computer science is first discussed. Then, different types of roles arising from an application case in the southern France Drôme river valley are described. The issue of roles composition and how it is resolved in the Drôme model is examined. The paper concludes on the contributions and on the limits that using roles brings to ABM modularity and expressivit

Environment design for emerging artificial societies

The NewTies project is developing a system in which societies of agents are expected to develop autonomously as a result of individual, population and social learning. These societies are expected to be able to solve the environmental challenges that they are set by acting collectively. The challenges are intended to be analogous to those faced by early, simple, small-scale human societies. Some issues in the construction of a virtual environment for the system are described and it is argued that multi-agent social simulation has so far tended to neglect the importance of environment design.agent-based modelling, stone age economics, economic anthropolgy