 Crossing borders as an art: practice and ethics of interface as basis of work-study programs 
The publications on pedagogical practices in work-study programs describes the interactions between the school-system and the work-system (Geay, 1991) and, to do this, uses the concept of interface-system. The main hypothesis put forward by this article is that putting this reliance into perspective is a factor of vigilance, uncertainty, and incessant questioning for those who are its actors. What do we mean by interface? What gaps and what contacts does it seek to translate, to make visible or even to provoke? The question is of urgent topicality at a time when alternation has become institutionalized and generalized, its vocabulary now forming part of a common heritage, the meaning of which must nevertheless continue to challenge us.