 It is commonplace to contrast how people render judgments, or make decisions, from how they ought to do so. However, interest in cognitive processes, mechanisms, and algorithms of boundedly rational judgment and decision making suggests that we instead distinguish among three aims of inquiry rather than these two. Briefly, a descriptive theory aims to explain or predict what judgments or decisions people in fact make; a prescriptive theory aims to explain or recommend what judgments or decisions people ought to make; a normative theory aims to specify a normative standard to use in evaluating a judgment or decision.