The question of knowledge construction can be regarded as a question of cognition in relation to action.Callon and al. have suggested interactive processes mixing both cognitive and social aspects of knowledge or technology. Both actors and interactions can usually be described by texts, and namely, by words. Thus knowledge development can be described through key-words network development. The authors have made simulations for knowledge development according to a local positive feed-back rule within small sets of word associations. In comparison with real data, the simulation results are fairly good. This approach leads to a general and very simple interaction model describing knowledge development. In this model, as opposed to usual cybernetics, actors constantly change, building a common scenario in relation to a mutual definition rule.