from the outset. However, identifying the appropriate leadership is challenging, and the committee concurs with the findings of the National Research Council (NRC 2005) on the characteristics of good leadership:
[Good leaders] are committed to progress and are capable of articulating a vision, entraining strong participants, promoting partnerships, recognizing and enabling progress, and creating institutional and programmatic flexibility. Good leaders facilitate and encourage the success of others. They are vested with authority by their peers and institutions, through title, an ability to control resources, or other recognized mechanisms. Without leadership, programmatic resources and research efforts cannot be directed and then redirected to take advantage of new scientific, technological, or political opportunities. (p. 48)
The choice of leadership structures and individuals may not be straightforward, but it is crucial to the success of the endeavor, with significant implications for how effectively the assessment is conducted and how well it is received by the target audience and other stakeholders. Effective assessment leaders respond easily to a changing political environment, provide transparent and legitimate rationale for such a response, and provide consistent messages to participants. In the best of circumstances, individuals with appropriate scientific credentials will naturally emerge, who enjoy the confidence of both the political and the scientific communities, have experience in conducting successful assessments, and are willing to undertake the present one. Since the leaders commonly function as spokespeople for the process, decisions regarding leadership must consider implications for perceptions of objectivity, credibility, and legitimacy.
Recommendation: The leadership and organizational structure of the assessment should be made clear, and the responsibilities of individuals and organizations well articulated.
Although multiple definitions of integrated assessments are being used by the community, the committee considers such assessments to result from a process that integrates social, biological, and physical sciences and engineering and allows interdisciplinary synthesis and analysis. Some integrated assessments are integrated after the fact, like the IPCC, and some are actually interdisciplinary and integrated from the beginning, such as the MA. Others, following a more restrictive use of the definition of integrated assessment, comprise a model that explicitly links the dynamics of