Ray C. Rist is a senior evaluation officer in the World Bank. He has served as university professor at the Johns Hopkins University, Cornell University, and George Washington University. His career has included fifteen years in the U.S. government in both the Executive and Legislative branches. He has authored, edited, or co-edited twenty-four books and written over 125 articles. Nicoletta Stame teaches social policy at the University "La Sapienza," Rome. She was a co-founder and first president of the Italian Evaluation Association. Her previous publications include L'esperienza della valutazione.