QUOTE : In cognitive science, the tendency to give different responses to problems that have surface dissimilarities but that are really formally identical is termed a framing effect. Framing effects are very basic violations of the strictures of rational choice. In the technical literature of decision theory, the stricture that is being violated is called descriptive invariance-the stricture that choices should not change as the result of trivial rewordings of a problem.2 Subjects in framing experiments, when shown differing versions of the same choice situation, overwhelmingly agree that the differences in the problem representations should not affect their choice. If choices flip-flop based on problem characteristics that the subjects themselves view as irrelevant-then the subjects can be said to have no stable, well-ordered preferences at all. If a person's preference reverses based on inconsequential aspects of how the problem is phrased, the person cannot be described as maximizing expected<br />utility. Thus, such failures of descriptive invariance have quite serious implications for our view of whether or not people are rational.