of all, supported by the general literature on organizational management (Blundel, 2004). Clear purposes reduce certain kinds of uncertainty for participants and thus reduce an impediment to high-quality thinking (e.g., Janis and Mann, 1977; Klein, 1996; Covello et al., 2001; Van den Bos and Lind, 2002). This research also shows, however, that uncertainty makes people more vigilant about evaluating the credibility of information sources (Half-acre, Matherey, and Rosenbaum, 2000; Brashers, 2001; Van den Bos, 2001) and leads their judgments about a process to be influenced more strongly by procedural fairness (Van den Bos, 2001; Van den Bos and Lind, 2002). In our judgment, the uncertainty of information for environmental decisions is almost always sufficient to trigger such effects, even when purposes are clearly stated. A process with clear purposes and procedural fairness is consistent with reducing these uncertainty-related cognitive effects.
In the context of environmental public participation, Wondolleck and Ryan (1999) have argued that agencies can engage in public participation processes as leader, partner, or stakeholder, and that when it is not clear which role an agency is playing, the process can suffer. This argument is borne out by empirical work on participation processes. For example, Bradbury (2005) found, in an examination of public participation in the cleanup of multiple Superfund sites, that clarity about agenda setting and prioritization of issues are important factors influencing the perceived competence, legitimacy, and capacity of public participation processes.
Leach’s (2005) review of 25 empirical studies of public participation in U.S.D.A. Forest Service decisions beginning in 1960 found strong evidence supporting the importance of focused scope and realistic objectives. Some of these studies highlighted the importance of clear purpose, goals, and objectives (Schuett, Selin, and Carr, 2001), along with measurable, quantifiable, or tangible goals (Doppelt, Shinn, and John, 2002). Others focused on the importance of defining results in terms of action rather than talk (U.S.D.A. Forest Service, 2000) and of focusing on attainable goals to build momentum, confidence, and reputation (Wondolleck and Yaffee, 1997). Findings highlighted the importance of addressing a manageable number of projects with a reasonable level of complexity (Daniels and Walker, 1997) and the importance of recognizing milestones throughout the process by setting and acknowledging short-term and long-term goals (U.S.D.A. Forest Service, 2000). Clarity in objectives of the process has also been found helpful for keeping decision processes focused on negotiable disputes rather than on discussion of values (Walters et al., 2003). The National Research Council (2007a) analysis of global change assessments, which examined a very different environmental context, concluded that a clear audience for an assessment product is essential to success, which also implies the importance of the processes having clear goals.
Conflicts about the scope of public participation efforts have often