Theories for Understanding the Effect of Impact Assessment and Project Evaluation on the Practice of Science.

We examine the phenomenon of impact assessment in the practice of scientific research, paying attention to the context in which project evaluation is used in federally funded research on plant health in the United States. Our analysis, which is derived from systems theory, carries out a particular view of the research process. For the purposes of this review, our use of the term systems theory references the body of interdisciplinary work that deals with the organization and function of complex structures in nature and human society. Key concepts in this body of theory are that both the components and the interactions among components are important in understanding behavior and that, frequently, systems are seen to be hierarchical in structure. The aim of our analysis is to bring to the attention of the plant health community several concepts from the social sciences that might help in understanding how researchers have responded to the increased expectations from funders to provide project evaluations and impact assessments. We generate a synthesis of these theories, which have not previously been used in a unified way, to explain choices in response to newly imposed goals. Although our analysis is motivated by a specific disciplinary focus on plant health, the issues we discuss are general. Thus, we hope the review is useful to a wide range of scientists, science program managers, and policymakers.