In the absence of key inputs from a number of individuals, the present report would have not been possible. First, I must express my sincere appreciation to Hans Gregersen, Chair of the CGIAR Standing Panel on Impact Assessment (SPIA), and Tim Kelley, SPIA Secretary, for critical guidance and feedback regarding the methodological approach pursued. I gratefully acknowledge the innumerable discussions of impact assessment methodologies held with these two individuals while conducting this analysis, which were crucial to development of criteria for the study review process. Thanks must also be expressed for the valuable suggestions and support provided by Shellemiah Keya, Executive Secretary of the CGIAR interim Science Council. In addition, I appreciate the assistance with formatting for final publication provided by Oksanna Hatalak and Tanya Alexander.
While reviewing individual studies, I received helpful input and clarifications from Derek Byerlee, Timothy Dalton, Robert Guei, Nancy Johnson, Aden Aw-Hassan, Victor Manyong, Phil Pardey and Greg Traxler. These responses greatly assisted my review efforts.
SPIA Members Ruben Echeverría and Herman Waibel, as well as interim Science Council Member Alain de Janvry offered useful suggestions regarding an early draft of this paper. Many thanks must also be expressed for the astute comments provided by the six external expert reviewers. These reflections have improved the cogency of this assessment, and have helped to contextualize the main findings.
