Norman, Kent L.Pleskac, TimothyConditional branching is used in surveys to direct respondents to skip inappropriate questions or to answer additional follow-up questions. When surveys are implemented on the World Wide Web, conditional branching can be automated in different ways. This study compares three implementations: (a) a manual form which replicates the paper-and-pencil version in a scrollable browser window, (b) a semi-automatic form which also shows the whole survey but auto-scrolls to the next appropriate question, and (c) an automatic form that displays only one item per screen and implements all branching. The surveys used for the study involved follow-ups of one, two, or three questions. The three implementations were counterbalanced in a within-subjects design. As expected it was found that completion times increased with the number of follow-up questions. More importantly, the automatic item-by-item implementation proved significantly faster than either the manual or the auto-scrolling versions. Respondents found the auto-scrolling to be disorienting. These results suggest that automatic branching should be used but with graceful jumps that guide the respondents' focus of attention without loosing it. Keywords Questionnaires, Surveys, Conditional Branching, User Interface, World Wide Web, CSAQ. (UMIACS-TR-2002-05) (HCIL-TR-2002-02)en-USTechnical Report