Albert Hirschman affirmed that "Judith Tendlers fine insights into the differential characteristics and side-effects of thermal and hydropower, and of generation and distribution, contributed in many ways to the formation of my views." Judith Tendler, in turn, wrote that Hirschman had taught her "to look where I never would have looked before for insight into a countrys development," and that in Alberts work a researcher who was "patient enough" would find "a rich complexity of both success and failure, efficiency alongside incompetence, order cohabiting with disorder." Reconstructing the theoretical roots of interpretive social science, this text shows how Hirschmans possibilism lies at the base of the original way Tendler practiced evaluation and anticipated many current developments. The continuing vitality of their thought enables us to trace the outlines of possibilist evaluation.

Sociologist Nicoletta Stame (PhD, State University of New York and Catania University) is emerita professor at Sapienza University of Roma, past president of the European Evaluation Society and Associazione Italiana di Valutazione, a member of the editorial board of Evaluation, and vice-president of A Colorni-Hirschman International Institute.