The numerous debates about the meaning and the usefulness of interdisciplinary research are often stuck in questions of definition or subtle distinctions between “pluridisciplinarity,” “multidisciplinarity,” “transdisciplinarity” or even “metadisciplinarity.” These distinctions do not shed much light on the reality of interdisciplinary practices. Do researchers see interdisciplinarity differently depending upon whether or not they belong to the main disciplines within their own institutions ? Are they sensitive to the fact that publishing in journals of another discipline does not increase their visibility ? Do all researchers collaborating within interdisciplinary projects share the same objectives ? Which obstacles do they encounter and what to they expect from their institutions ? The analysis presented here focuses on the interests of researchers to engage in interdisciplinary projects, on their perception of the obstacles that they encounter as they work toward their goals, and on the organizational constraints. Beyond the differences related to the degree of advancement in their careers, the researchers who choose to invest in inter-sectoral collaborations agree on a specific requirement : the loosening of the short-term academic constraints that hinder interdisciplinary explorations, by definition slower and more uncertain.