Interdisciplinarity is as trendy as it is difficult to define. We propose three different operationalizations of a discipline and two levels (article or laboratory) of integration of these disciplines. This leads to six indicators of interdisciplinarity, achieving a rich characterization of laboratories publication practices. Thanks to a statistical analysis of these indicators on 600 CNRS laboratories, we suggest that, besides an average value of interdisciplinarity, different laboratories can be distinguished by the "distance" between the disciplines in which they publish and by the level of interdisciplinary integration (article or laboratory).
