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12 Participatory Approaches 257

Secondly, interactive use of a simulation model is a means to keep some of these
links open and active, with participants as driving belts. Stakeholders are embedded
in social networks which cross the boundaries into the physical and environmental
networks. They make the links come alive, which allows them to function and be
updated.
There is thus a need to question the boundaries set in the interactive setting:
actors in the neighbourhood, concerns of actors connected to those tackled by the
(simulation) model and how these relations are to be mobilised in the interaction.

12.2.1.2 Distribution of Control

A key characteristic of social systems which is to be addressed through social
simulation is their complexity. This complexity leads to various consequences, such
as the emergence of phenomena, delay effects or discontinuities in some trends,
which are present in social systems as in any complex systems. These are usually
the effects which one likes to discover or better understand when experimenting
with social simulations. From the internal point of view of simulations, Schelling
has shown experimentally that reproducing settings with multiple decision centres
improves the quality of representation of complexity (Schelling 1961). He could
generate complexity through experimental games because of the presence of
independent decision centres, the players. This result has also been shown with
simulations used for forecasting (Green 2002). Green compared the capacity of
forecasting the outcome of past social conflicts with a role-playing game with
students, game theorists and a group of experts. He compared the simulated
outcomes with those from the real negotiations and found that the role-playing game
setting produced the best results. This was the one with the main distribution of
decisions among autonomous centres.
The purpose of associating participatory processes and social simulation here
is then to increase the complexity through interactive use or implementation of
a social model. Unless computational agents are effectively used, which is rare
(Drogoul et al. 2003), formal theories of complex systems that are completely
embedded in a simulation model do not simulate complex patterns but implement an
explanation of a complex pattern. In other words, they should be implemented in a
distributed setting with autonomous entities. Participatory approaches provide such
settings. There is then an issue of a deep connection between a simulation model
and participants in a participatory modelling setting.

12.2.2 Improving Suitability of Simulation Model’s Use

Quality of a model is also assessed according to its suitability for its intended
use. In this subsection, two cases of use are considered: knowledge increase and
policymaking. In both cases, it is expected that involvement of stakeholders at any