The negotiation-mediation process is one of power exchange. Unless the parties to a dispute have some relative ability to exercise sanctions over one another, there is little chance of successful mediation. Two different and important phases are involved in the decisionmaking process in environmental concerns: establishing priorities and then developing programs to accomplish those priorities. The composition of environmental groups, the tactics they use, and the roles they play differ widely from the characteristics of protest constituencies in other kinds of social conflict. One of the most striking characteristics of most environmental groups is their homogenous membership. Environmental groups know from experience that they can effectively delay implementation of a project, but that total victory is difficult. The social standing of environmentalists permits them to be comfortable and effective when operating with the political process. A proven approach in environmental conflicts has been to help the parties establish a list of priorities and assumptions, develop technical solutions based on the listing, and then become involved in a dispute over solutions, even though the real dispute may be over the ranking of priorities. The mediator can play an additional role by drawing in outside technical resources.