We explore the practical difficulties of interdisciplinary research in the context of a regional- or local-scale project. We posit four barriers to interdisciplinarity that are common across many disciplines and draw on our own experience and on other sources to explore how these barriers are manifested. Values enter into scientific theories and data collection through scientists' hidden assumptions about disciplines other than their own, through the differences between quantitative and interpretive social sciences, and through roadblocks created by the organization of academia and the relationship between academics and the larger society. Participants in interdisciplinary projects need to be self-reflective about the value judgments embedded in their choice of variables and models. They should identify and use a core set of shared concerns to motivate the effort, be willing to respect and to learn more about the "other" be able to work with new models and alternative taxonomies, and allow for plurality and incompleteness.