This paper introduces this Special Issue on the Role of Contextual Factors in Common Pool Resource (CPR) research and provides an introduction to CPR theory. It advocates an interdisciplinary, holistic approach to natural resource policy analysis, which assumes the entire resource system, and the wider social, cultural, ecological and economic environment in which it is embedded, as the correct subject for research. The paper recognizes the need to examine how different users of resource systems interrelate and how each relates to their environment. It calls for more diachronic research and for research that extends beyond the geographical boundaries of a particular resource system. Contextual analysis must be focused at different levels. While contextual factors vary from resource situation to resource situation, generic categories of factors may be useful. The uncertainty of contextual influence demands that a balance is struck between the need for flexible management regimes, which allow users to adapt to changing contexts, and the need for stable, long-term resource management planning. The ability to incorporate the knowledge systems of the user groups into policy and management frameworks may determine the extent to which they are able to adapt to change in time to prevent resource deterioration. In doing so, the researcher should be aware that both the research and researcher are contextual factors that may become internalized. Copyright © 1999 John Wiley & Sons, Ltd.