Users often must browse hierarchies with thousands of nodes in search of those that best match their information needs . The PDQ Tree - browser (Pruning with Dynamic Queries) 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 . Sub-trees of unselected nodes are pruned out , leading to compact views of relevant nodes . Usability testing of the PDQ Tree-browser , done with eight subjects , helped assess strengths and identify possible improvements . The PDQ Tree-browser was used in Network Management (600 nodes) and UniversityFinder (1100 nodes) applications . A controlled experiment , with 24 subjects , showed that pruning significantly improved performance speed and subjective user satisfaction . Future research directions are suggested . ÷ 1997 Academic Press Limited .
['Harsha Kumar', 'Catherine Plaisant', 'Ben Shneiderman']
Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning