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