The model elaboration was incremental, with some major changes during the project. These changes are of course related to important changes in the view of the modelling problem, and the possible technical solutions.

In a first phase, we explored several directions of modelling (see corresponding part of the final report). 

The Ecole Normale Supérieure proposed different models directly derived from the classic innovation diffusion threshold model. 

University Of Surrey proposed different variants of a model of the exanges of opinions about the measure between the farmers.

University Of Milan proposed a multi-criteria framework to the decision of adoption. 

Cemagref (DFCF) studied a knowledge based approach for modelling the decision process (referring to KADS) (pdf format 396ko, in French).

Then we begun to converge to a synthetic model, based on a multi-criteria representation of t ofhe decision process connected to a model social influence on opinions (see corresponding part of the final report). A first version of this model was tested on two study zones :  Breadalbane ESA (pdf format 502ko), and organic farming in Allier (pdf format 1107ko, in French).

In a third phase, we refined and improved this model (see corresponding part of the final report). This work is decribed in more details in "the core model" of "the model applied to the study zones".