Abstract
An experiment teacher of elementary school try te become an educational adviser. He accepts the collaboration with the researchers, the first one in didactics of history and the second in professional didactics, to get success with examination necessary to become an educational adviser. The didactic experiment concerns an historical debate with pupils to orient them in an historic investigation from an engraving dating from 1787. The analyse shows that the didactic experiment was abandoned for the benefit of institutional prescriptions in which this teacher aims to conforms, its principles of actions and the significantly associations with his future job. It’s in contradiction with the sens of the activity proposed by the researcher in didactics of history. Our longitudinal analysis concerns, first, the teacher analyses the activity of a beginner, second, the experimentation of the debate in his classroom and finally his theorization about the driving of this type of debate in a document required in the examination.