An evaluation of space-filling information visualizations for depicting hierarchical structures

A variety of information visualization tools have been developed recently, but relatively little effort has been made to evaluate the effectiveness an d utility of the tools. This article describes results from two empirical s tudies of two visualization tools for depicting hierarchies, in particular, computer file and directory structures. The two tools examined implement s pace-filling methodologies, one rectangular, the Treemap method, and one ci rcular, the Sunburst method. Participants performed typical file/directory search and analysis tasks using the two tools. In general, performance tren ds favored the Sunburst tool with respect to correct task performance, part icularly on initial use. Performance with Treemap tended to improve over ti me and use, suggesting a greater learning cost that was partially recouped over time. Each tool afforded somewhat different search strategics, which a lso appeared to influence performance. Finally, participants strongly prefe rred the Sunburst tool, citing better ability to convey structure and hiera rchy. (C) 2000 Academic Press.