The article dreads the sessions of educational advice during the training courses of practice accompanied with the professors trainees of the French public agricultural education, from the model of the situations of supervision proposed by Jérôme Bruner. His objective is to describe the professional knowledges mobilized by the educational advisers to allow the learnings of their trainees.

The analysis of the recording of 14 sessions of debriefing allows to spot (locate) the implementation of six functions(offices) of the propping up which defined Bruner ( characteristics of the situations of supervision(guardianship) and grouped together(included) " relational function (office) " and " function(office) of guidance " and " function(office) of intervention ") and so gives evidence of the mobilization of specific professional knowledges in the educational advice(council).

Four families of knowledges were able to be identified, the professional knowledges relative to the institution of the dialogue, the professional knowledges relative to the theorization of the experience(experiment), the professional knowledges relative to the inference and the professional knowledges relative to the evaluation