The purpose of this thesis is to give an account on a field of practical experiences that is shifting and insufficiently known : scientific animation examined on one hand from a documentary study and on the other hand from the study of practices observed in situ. The "scientific animation" is observed in its socio historical context and it brings out various roles for the "animateur" in line with intentions and with different social and cognitive proposes. The analysis of the present day set up shows a grant variety of actors and forms of "animation". Three associations of French scientific and technical culture are more particularly considered because they emphasize the practical and experimental activities as a means of teaching to science : Graine de Chimiste, ANSTJ, Les Petits Débrouillards. These three associations appear in the current set up of scientific animation in an institutional framework and seen from the angle of various form of animation. The studies are carried out in accordance with an approach to the ethnography of practice and centered on the analysis of the "animation's" rhetoric, with limited work groups making a technical or manufactured objects with 9-11 year olds and training courses for the "animation". Three main lives are considered situation (location and material conditions), communication (interaction of language), epistemology (knowledge at work). The result of the analyses (chronological, propositional and analysis of the exchanges) reveal procedures of "animation" that are particular to each association : a very strict protocol of manufacturing for Graine de Chimiste the drafting of a project for ANSTJ, an interactive method for Les Petits Débrouillards. What makes the original feature of the animation is the fact that it offers activities outside the restrictive framework of school. The public can experience original situations that may enrich their knowledge of the world of manufactured or technical objects.
