Color, Labels, and Interpretive Heuristics for Response Scales

We carried out two experiments to investigate how the shadingof the options in a response scale affected the answers to thesurvey questions. The experiments were embedded in two web surveys,and they varied whether the two ends of the scale were representedby shades of the same or different hues. The experiments alsovaried the numerical labels for the scale points and examinedresponses to both unipolar scales (assessing frequency) andbipolar scales (assessing favorability). We predicted that theuse of different hues would affect how respondents viewed thelow end of the scale, making responses to that end seem moreextreme than when the two ends were shades of the same hue.This hypothesis was based on the notion that respondents usevarious interpretive heuristics in assigning meaning to thevisual features of survey questions. One such cue is visualsimilarity. When two options are similar in appearance, respondentswill see them as conceptually closer than when they are dissimilarin appearance. The results were generally consistent with thisprediction. When the end points of the scale were shaded indifferent hues, the responses tended to shift toward the highend of the scale, as compared to scales in which both ends ofthe scale were shaded in the same hue. Though noticeable, thisshift was less extreme than the similar shift produced whennegative numbers were used to label one end of the scale; moreover,the effect of color was eliminated when each scale point hada verbal label. These findings suggest that respondents havedifficulty using scales and pay attention even to incidentalfeatures of the response scales in interpreting the scale points.