Contrast Effects in Consumer Judgments: Changes in Mental Representations or in the Anchoring of Rating Scales?

Contrast effects in consumers judgments of products can stem from changes in how consumers mentally represent the stimuli or in how they anchor rating scales when mapping context-invariant mental representations onto those scales. We present a framework for distinguishing between these types of contrast effects on the basis of whether changes in mean ratings of multiattribute stimuli are accom-panied by evidence of changes in their rank order. We also report two empirical studies. In study 1, mean overall ratings of a core set of car profiles showed contrast effects due to manipulations of the ranges of gas mileage and price in several sets of context profiles. Diagnostic tests implied that these effects reflected changes in response-scale anchoring rather than in mental representations. In study 2, consumers high and low in knowledge of automobile prices showed equally large contrast effects on ratings of the expensiveness of a core set of real cars. Diagnostic tests showed that these reflected true changes in mental representation for low-knowledge consumers but only changes in scale anchoring for more knowledgeable ones. Thus, ostensibly similar context effects on simple ratings have different un-