Evaluating the impacts of boundary-spanning activities at the interface of environmental science and policy: A review of progress and future research needs

Environmental organizations, programs, and research efforts are increasingly interested in spanning the boundaries between science and policy so that decision making processes are informed by the most current and best available scientific knowledge. 'Boundary spanning' is a practice that has been developed to help in this regard, by enabling knowledge exchange between communities of science and policy and actively shaping complex science-policy landscapes. However, despite an increasing number of claims about the benefits that can arise as a result of boundary-spanning activities, more work is needed to evidence and demonstrate the impacts of boundary-spanning efforts. This is a challenging prospect as such impacts occur in complex social and ecological systems; involve subtle, gradual, and difficult-to-track changes; and elude conventional evaluation methods that fail to capture the complexity of real world science and decision making contexts. Understanding, evaluating, and demonstrating impacts would strengthen the boundary spanning field by helping to clarify general principles for what success looks like and how to measure it. In the near term, evaluation as a core component of growing a community of practice can motivate practitioners to articulate specific intended outcomes, orient toward common goals, and compare impacts across different cases. In the long term, more thoughtful evaluation can improve the effectiveness of boundary spanning and further contribute to the development of a professional community of practice. This paper reflects on the current practice of boundary spanning, reviews studies that demonstrate the impact of boundary-spanning activities through different methodological approaches, and recommends future directions for research and practice relating to impact evaluation.