The role of attribute knowledge and overall evaluations in comparative judgment

Comparisons are often characterized by a directional feature-matching process in which individuals examine the extent to which the features of one alternative-the "subject"-are present or absent in a second alternative-the "referent." Previous research cf. (Tversky, 1977; Houston, Sherman, & Baker, 1989) has found that individuals exhibit a pervasive tendency to focus upon the unique features of the subject and to neglect the unique features of the referent during the comparison process (the direction-of-comparison effect). Experiment 1 examined how the availability of overall evaluations in memory influences the direction-of-comparison effect and comparison strategy selection. When overall evaluations toward the choice alternatives were available, respondents were less likely to show a directional bias and neglect the unique features of the referent in making a preference judgment. The findings suggest that the availability of overall evaluations decreases the likelihood of a feature-based comparison. Experiment 2 examined the robustness of the direction-of-comparison effect when feature-based comparisons are performed. The direction-of-comparison effect was found when the features of two alternatives were from different dimensions, but not when the features occupied different points on the same dimension. The results suggest that directional effects in preference judgments depend on the availability of overall evaluations and on the nature of the features involved in the comparison process.