Ck. Hsee et al., Preference reversals between joint and separate evaluations of options: A review and theoretical analysis, PSYCHOL B, 125(5), 1999, pp. 576-590
Arguably, all judgments and decisions are made in 1 (or some combination) o
f 2 basic evaluation modes-joint evaluation mode (JE), in which multiple op
tions are presented simultaneously and evaluated comparatively, or separate
evaluation mode (SE), in which options are presented in isolation and eval
uated separately. This article reviews recent literature showing that peopl
e evaluate options differently and exhibit reversals of preferences for opt
ions between JE and SE. The authors propose an explanation for the JE/SE re
versal based on a principle called the evaluability hypothesis. The hypothe
sis 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 t
han in SE.