The contributions to Testing Scientific Theories are unified by an interest in responding to criticisms directed by Glymour against existing models of confirmation–-chiefly H-D and Bayesian schemas–-and in assessing and correcting the “bootstrap“ model of confirmation that he proposed as an alternative in Theory and Evidence (1980). As such, they provide a representative sample of objections to Glymour's model and of the wide range of new initiatives in thinking about scientific confirmation that it has influenced. The effect is a sense of engagement and focus, and of significant advance at least in articulation of the problems that require solution; as Earman observes, “it is … heartening to report that the various opposing camps learned from each other” (p. vi). In what follows I am concerned to assess what has been learned both critically, about Glymour's model, and constructively about the resources of the alternatives he challenges. My thesis is that while the theories emerging in this debate do deal with a wider range of scientific practice than before, their remaining limitations raise important questions about the ambitions and criteria of adequacy that have traditionally governed philosophical inquiry in this area.