---
id: communication/companion-modelling
about:
  group: Playing
  label: Companion modelling (ComMod)
  description: >-
    Participatory research approach from a group of mainly CIRAD scientists that
    builds role-playing games and agent-based models together with the people
    who use the land or resource.
  tags:
    - participatory modelling
    - role-playing games
    - agent-based model
    - natural resource management
    - CIRAD
    - Cormas
article:
  url: 'https://www.jasss.org/6/2/1.html'
  published: '2003-03-31'
  publisher: Journal of Artificial Societies and Social Simulation
  authors:
    - Olivier Barreteau
    - Martine Antona
    - Patrick d'Aquino
    - Sigrid Aubert
    - Stanislas Boissau
    - François Bousquet
    - William's Daré
    - Michel Etienne
    - Christophe Le Page
    - Raphaël Mathevet
    - Guy Trébuil
    - Jacques Weber
domains:
  - people
  - places
  - ecology
  - food
open:
  source: unknown
  data: unknown
  api: unknown
  participation: open
  note: >-
    The 2003 charter is free to read in JASSS. Cormas, the agent-based platform
    its authors pointed to, is under the MIT licence.
provenance:
  origin: agent
  sources:
    - title: 'Our Companion Modelling Approach (Barreteau and others, JASSS, 2003)'
      url: 'https://www.jasss.org/6/2/1.html'
    - title: 'ComMod: La modélisation comme outil d''accompagnement (the group''s site)'
      url: 'https://www.commod.org/'
    - title: 'La modélisation d''accompagnement : une posture (ComMod)'
      url: 'https://www.commod.org/qui-sommes-nous/posture'
    - title: Association ComMod (ComMod)
      url: 'https://www.commod.org/qui-sommes-nous/association'
    - title: >-
        Companion Modelling: A Participatory Approach to Support Sustainable
        Development (Étienne, ed., Springer and Quae, 2014)
      url: 'https://link.springer.com/book/10.1007/978-94-017-8557-0'
    - title: Cormas (CIRAD)
      url: 'https://cormas.cirad.fr/'
  created: '2026-10-23'
  reviewed: '2026-10-23'
  reviewed_by: >-
    Claude, from the charter, the group's own pages and the book's publisher
    page; the book's chapters were not read
  status: draft
---
Companion modelling, ComMod for short (in French, modélisation d'accompagnement), is a way of building a model of how people share a renewable resource, such as land, water or forest, together with the people concerned.[^1,2] The main tools are role-playing games and agent-based models, computer simulations in which each farmer, herder or household is a separate actor with its own rules.[^1,2] In practice a researcher draws up a first model of how the place works, puts it in front of the people concerned through simulations or role-playing games, and revises or rebuilds it from what they say and do.[^1] The cycle of field work, modelling, simulation and field work again repeats, and leaves a family of models rather than one finished one.[^1]

The approach was set out in 2003 as a charter in the Journal of Artificial Societies and Social Simulation.[^1,3] Its twelve signatories came from CIRAD, Cemagref, INRA, the Tour du Valat and the IFB.[^1] Among them were the CIRAD modellers François Bousquet and Christophe Le Page, the Cemagref water scientist Olivier Barreteau and the INRA plant ecologist Michel Etienne.[^1] A French version was finalised in 2004, and a shorter text for a wider audience in 2013.[^3] The charter calls it a scientific stance rather than a modelling handbook, and the model "merely an intermediary object" for shared thinking.[^1]

The charter gives it two uses. One is to understand a system: researchers and local people learn together, and the model seeks "a mutual recognition of everyone representation" of the problem rather than simplifying what people know.[^1] The other is to support a collective decision, by making each party's points of view and criteria explicit.[^1] Here the charter says the aim is not the best solution but a better process, and that the scientific view is one among others.[^1] Every assumption behind the model is meant to be discarded after each round in the field, which is to say put up for refutation.[^1]

The group's main book in English is Companion Modelling: A Participatory Approach to Support Sustainable Development, edited by Michel Étienne (Springer, 2014, copyright Éditions Quae).[^5] A French collective book on the approach came out from Quae in 2010.[^2] The English book's chapters cover models for sharing representations, power imbalances between participants, assessing the effects, and passing the approach on. It includes 27 case studies and 7 teaching tools.[^5] The ComMod association runs a discussion forum and regular training schools; the 2026 school was held in Montpellier from 7 to 11 September with 13 participants.[^2,4] Cormas, CIRAD's agent-based modelling platform for relations between societies and their environment, is close to the group: the charter asked new signatories to register through the Cormas website, and the Cormas site offers the approach.[^1,6] Cormas is free under the MIT licence.[^6]

Here the people concerned meet the model while it is still being built, and what they say and do in the game changes it.