Réflexion sur la construction de quelques concepts scientifiques des sciences physiques. Repérages du « sens » lié à l'émergence d'invariants -- en situation d'apprentissage -- pour la formation des maîtres.

We try to identify -- in a learning situation -- clues related to the emergence of invariants related to three concepts of the field of physical sciences (mass, moment of a force, chemical element). We seek and analyze within the didactic interactions (more particularly the exchanges of representations between actors), the relevance of the indices, pathways that characterize and give meaning to the construction of the concepts. [ABSTRACT FROM AUTHOR]