Interacting with Huge Hierarchies: Beyond Cone Trees

Abstract This paper describes an implementation of a toolfor visualizing and interacting with huge information hier-archies, and some preliminary empirical evaluation of thetool’s efficacy. Existing systems for visualizing huge hier-archies using cone trees ‘‘break down” once the hierarchyto be displayed exceeds roughly 1000 nodes, due to in-creasing visual clutter. This paper describes a systemcalledfsviz which visualizes arbitrarily large hierarchieswhile retaining user control. This is accomplished by aug-menting cone trees with several graphical and interactiontechniques: usage-based filtering, animated zooming,hand-coupled rotation, fish-eye zooming, coalescing of dis-tant nodes, texturing, effective use of colour for depth cue-ing, and the applications of dynamic queries. Thefsvizsystem also improves upon earlier cone tree visualizationsystems through a more elaborate node layout algorithm.This algorithm enhances the usefulness of cone tree visual-ization for large hierarchies by all but eliminating clutter.