Gerard Vergnaud’s theory of conceptualisation through action is at the heart of the analyses put forward by the ANPLACE (analyse plurielle de l’accompagnement par l’écriture or plrual analysis of accompaniment through writing) on the basis of professional narratives produced by its members to better understand the development of competencies in the fields of nursing and popular education. The play of interaction between the writing up of professional situations and the different levels of explicitation demanded by the exercice enables their complexity as well as the need to gain in intelligibilty to emerge. This dynamics of a search for meaning creates an environment propitious for the assimilation of elements of Vergnaud’s theory which can be shared because they are operational. By privileging a relatively long time frame and the repetitivity of its protocol, ANPLACE thus promotes a double dynamism of action towards its verbalisation and vice-versa (operational and predicative forms of knowledge). The lexical precision dear to Vergnaud thus turns out to be a strong point of leverage for the development of each member of the collective.