Kumar, H. (December 1994)
Users often must browse hierarchies with thousands of nodes in search of those that best match their information needs. The Tree-browser visualization tool was specified, designed and developed for this purpose. This tool presents trees in two tightly-coupled views, one a detailed view and the other an overview. Users can u se dynamic queries, a method for rapidly filtering data, to filter nodes at each level of the tree. The dynamic query panels are user-customizable. Subtrees of unselected nodes are prned out, leading to compact views of relevant nodes. The software architecture, data structures and algorithms used to achieve this behavior are specified. Usability testing of the Tree-browser, done with 8 subjects, helped assess strengths and identify possible improvements. The Tree-browser was applied to the Network Management (600 nodes) and UniversityFinder (1100 nodes) applications. Future research directions are suggested.