The companion modelling approach initially was conceived and tested at a local level because of the focus on resource users. Based on the premise that different stakeholders involved in resource management operate with different areas of reference and time scales in mind, the approach focuses on the representation of this diversity in its tools and in the form of coordination workshops (d'Aquino et al. 2002b; Étienne et al. 2008c; Le Page et al. 2001). Like many participatory approaches developed at the local level, the approach quickly confronted issues posed by the institutionalization of participatory processes (Pimbert 2004): the institutional integration of collective learning developed at a local level, taking into account stakeholders not present at the local level, and the need to interact directly with regulators and decision-makers at higher levels. A study group was formed within the ComMod network, in parallel to the ADD-ComMod project, to discuss the novel challenges raised by the application of companion modelling to several organizational levels of action and decision and by changing scales in a companion modelling approach.