How does response bias emerge in lengthy sequential preference judgments?

Internet surveys are currently used in many academic and marketing research fields. However, the results for these surveys occasionally show traces of response bias. In our study, we analyzed how response bias appears in lengthy preference judgments. 1042 respondents participated in lengthy sequential preference judgments. Three stimuli series were used: scene pictures, Attneave nonsense shapes, and point-symmetric figures. One hundred stimuli were selected for each series and individually displayed on a computer screen, with presentation order randomized for each respondent. Respondents were then asked to rate their degree of preference for each stimulus. Mean preference scores increased over the first 10–20 trials, then, gradually decreased from the middle to the last trial. Furthermore, participants tended to produce the maximum and minimum score during early trials. These results demonstrated that response bias can be a function of presentation order.