A Comparison of Pan and Zoom and Rubber Sheet Navigation

As information visualization tools are used to visualize datasets of increasing size, there is a growing need for techniques that facilitate efficient navigation. Pan and zoom navigation enables users to display areas of interest at different resolutions. Focus+context techniques aim to overcome the drawbacks of pan and zoom by dynamically integrating areas of interest and context regions. To date, empirical comparisons of these two navigation paradigms have been limited in scope and inconclusive. In two controlled studies, we evaluated navigation techniques representative of the pan and zoom and focus+context approaches. The particular focus+context technique examined was rubber sheet navigation, implemented in a way that afforded a set of navigation actions similar to pan and zoom navigation. The two techniques were used by 40 subjects in each study to perform a navigation-intensive task in a large tree dataset. Study 1 investigated the effect of the amount of screen real estate devoted to context regions for each navigation technique. Performance with both techniques was not significantly affected by this factor, but was influenced by technique-specific strategies developed by subjects. Study 2 compared the performance of the two techniques. Pan and zoom navigation was found to be faster than rubber sheet navigation and was rated by subjects as easier and less mentally demanding. We discuss the implications of these results, including the relationship between navigation technique, task, and user strategy, and propose directions for future work.