Preference reversals between joint and separate evaluation of options: A review and theoretical analysis

Arguably, all judgments and decisions are made in 1 (or some combination) of 2 basic evaluation modes—joint evaluation mode (JE), in which multiple options are presented simultaneously and evaluated comparatively, or separate evaluation mode (SE), in which options are presented in isolation and evaluated separately. This article reviews recent literature showing that people evaluate options differently and exhibit reversals of preferences for options between JE and SE. The authors propose an explanation for the JE/SE reversal based on a principle called the evaluability hypothesis. The hypothesis posits that it is more difficult to evaluate the desirability of values on some attributes than on others and that, compared with easy-to-evaluate attributes, difficult-to-evaluate attributes have a greater impact in JE than in SE. In normative accounts of decision making, all decisions are viewed as choices between alternatives. Even when decision mak-ers appear to be evaluating single options, such as whether to buy a particular car or to go to a certain movie, they are seen as making implicit trade-offs. The potential car owner must trade off the benefits of car ownership against the best alternative uses of th