Discussion papers

CPM-17-238 - 27 June 2017

Discussion Paper: Five Modelling Purposes

Bruce Edmonds

A draft of a chapter that discusses some different purposes for a simulation model and the consequences of this in terms of its development, checking and justification.

How one builds, checks, validates and interprets a model depends on its ‘purpose’. This is true
even if the same model is used for different purposes, which means that a model built for one
purpose but now used for another may need to be re-checked, re-validated and maybe even rebuilt
in a different way. Here we review some of the different purposes for building a simulation
model of complex social phenomena, focussing on five in particular: theoretical exposition,
prediction, explanation, description and illustration. The chapter looks at some of the
implications in terms of the ways in which the intended purpose might fail. In particular, it looks
at the ways that a confusion of modelling purposes can fatally weaken modelling projects,
whilst giving a false sense of their quality. This analysis motivates some of the ways in which
these ‘dangers’ might be avoided or mitigated.

This is a draft of the text that will be in the next edition of, due this year 2017.

Edmonds, B. & Meyer, R. (2013) Simulating Social Complexity – a handbook. Springer.

A more up-to-date version of this paper, which covers 7 modelling purposes as well as different model development strategies can be found at: http://cfpm.org/file_download/186/Different+Modelling+Purposes-JASSS-v1.6.pdf