The Editorial Projects in Education Research Center, with support from the Thomas B. Fordham Foundation, has conducted a study of the factors that have influenced the educational policy landscape during the past decade. Using a two-stage survey methodology, leading education-policy experts were asked first to identify and then to rate highly influential agents or "Influentials" across four different categories--Studies, Organizations, People, and Information Sources. Influence scores and rankings for the leading nominees in each category were reported. As the study's results demonstrate, there are strong interconnections among these four dimensions of influence. Certain institutions, for example, appear in multiple categories, represented as prominent organizations, the homes of renowned experts, and sponsors of leading studies and information sources. This report offers a first attempt at untangling the complex web of influence that has helped to shape education policy over the years. The full report describes the study's methodology in greater detail and provides in-depth profiles for the top-ranked nominees in each of the four influence categories. Appended are: (1) Complete Listing of Nominees in First-Round Survey; and (2) Survey Instruments. (Contains 17 exhibits.) [This report was produced by the Editorial Projects in Education (EPE) Research Center.]