Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning

Abstract

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 use 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 pruned out, leading to compact views of relevant nodes.<P>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) application. Future research directions are suggested.