Testing of the 'reduction of compound alternatives' principle

This paper reports an empirical investigation of the effects of three pictorial forms of problem representation on conformance with the Reduction of Compound Alternatives Principle of expected utility theory. The most common form of representation, written problem statements, was compared with three pictorial representations: tubes containing one hundred labeled balls, decision matrices with each column proportional in size to the probability of the corresponding event, and bar graphs. The tubes representation led to fewer violations of the Principle. In addition, when subjects were trained to construct proportional matrices from written problem statements, they exhibited fewer violations than those who received the same problems already formatted in proportional matrices. The results reported here should contribute to the development of a theory of the way people frame decision problems.