In interdisciplinary research scientists have to share and integrate knowledge between people and across disciplinary boundaries. An important issue for philosophy of science is to understand how scientists who work in these kinds of environments exchange knowledge and develop new concepts and theories across diverging fields. There is a substantial literature within social epistemology that discusses the social aspects of scientific knowledge, but so far few attempts have been made to apply these resources to the analysis of interdisciplinary science. Further, much of the existing work either ignores the issue of differences in background knowledge, or it focuses explicitly on conflicting background knowledge. In this paper we provide an analysis of the interplay between epistemic dependence between individual experts with different areas of expertise. We analyze the cooperative activity they engage in when participating in interdisciplinary research in a group, and we compare our findings with those of other studies in interdisciplinary research.