  This paper gives an introduction to this issue, and presents the framework
and the main steps of the Rosa project. Four teams of researchers, agronomists,
computer scientists, psychologists and linguists were involved during five
years within this project that aimed at the development of a knowledge based
system. The purpose of the Rosa system is the modelling and the comparison of
farm spatial organizations. It relies on a formalization of agronomical
knowledge and thus induces a joint knowledge building process involving both
the agronomists and the computer scientists. The paper describes the steps of
the modelling process as well as the filming procedures set up by the
psychologists and linguists in order to make explicit and to analyze the
underlying knowledge building process.
