Understanding the Effect of Information Presentation Order and Orientation on Information Search and Treatment Evaluation

Background. Past research finds that treatment evaluations are more negative when risks are presented after benefits. This study investigates this order effect: manipulating tabular orientation and order of risk–benefit information, and examining information search order and gaze duration via eye-tracking. Design. 108 (Study 1) and 44 (Study 2) participants viewed information about treatment risks and benefits, in either a horizontal (left-right) or vertical (above-below) orientation, with the benefits or risks presented first (left side or at top). For 4 scenarios, participants answered 6 treatment evaluation questions (1–7 scales) that were combined into overall evaluation scores. In addition, Study 2 collected eye-tracking data during the benefit–risk presentation. Results. Participants tended to read one set of information (i.e., all risks or all benefits) before transitioning to the other. Analysis of order of fixations showed this tendency was stronger in the vertical (standardized mean rank difference further from 0, M = ±.88) than horizontal orientation (M = ± 0.71). Approximately 50% of the time was spent reading benefits when benefits were shown first, but this was reduced to ~40% when risks were presented first (regression coefficient: B = −4.52, p <.001). Eye-tracking measures did not strongly predict treatment evaluations, although time percentage reading benefits positively predicted evaluation when holding other variables constant (B = 0.02, p =.023). Conclusion. These results highlight the impact of seemingly arbitrary design choices on inspection order. For instance, presenting risks where they will be seen first leads to relatively less time spent considering treatment benefits. Other research suggests these changes to inspection order can influence multi-option and multi-attribute choices, and represent an area for future research