Two papers for Yusuf Goolamabba's talk on 03/01/96:

Tree-Maps: A Space-Filling Approach to the Vizualization of Hierarchical Information Structures - Brian Johnson and Ben Shneiderman
Information Vizualization using 3D Interactive Animation Robertson, Card and Mackinlay

Tree-Maps: A Space-Filling Approach to the Vizualization of Hierarchical Information Structures

An innovative method for vizualizing hierarchical structured information is described. The main selling point of this point is that this mechanism makles full use of available display space, unlike competing techniques like listings (which provides for detail but is very poor at presenting structural information), outlines (which provides for both structural and content info, but only a few lines at a time) and tree drawing (poor use of space and lack of content information) The author motivates the the architecure by looking at current metaphors for viewing directory structures. Use of color is and effective mthod to provide content information. Algorithms for generating the Tree Map is also given in the paper Tree Map's seem most effective if the hierarchy they visualize is well defined like teams in a league and players in team. I am not sure, if directory structures are so well defined. Also, the fact that sub-levels are recursively rotated 90 degrees is not obvious at first

Question: It seems that if you have a directory, with subdirectories and subdirectories and some intermediate node,because of the repeated rotation, one would lose sense of the directory structure quickly. Is there any cognitive artifact like color, sound which can help in determing where you are in the hierarchy

Information Vizualization using 3D Interactive Animation

This paper looks at the inability of current desktop metaphors which are incapable of scaling to the level required for next generation of applications , which lead to information explosion ( The Web is a prime example of this) They suggest four methods for improving the cost structure of information access

Large Workspace
Agents
Real-Time Interaction
Visual Abstractions

They describe a UI Architecture which and talk about the following problems which were addresses

The Multiple Agent Problem
The Animation problem
The Interaction Problem
Rhe Viewpoint Movement Problem
The Object Movement Problem
The Small Screen Space Problem

The heart of the Information Visualizer is a controlled resource scheduler, the Cognitive Coprocessor architecture whch schedules agent. Search Agents search for documents by relevane feedback. The basic building block in the Information Vizualizer are Interactive Objects which combine user interaction and agent interaction. To Naviage within 3D scpae, the Information Vizualizer has five metaphors

The Walking Metaphor
Point of Interest Logarithmic Flight
Object of Interest Logarithmic Manipulation
Doors
Overview

For Classical data, the following metaphors were explored

Hierarchichal: Cone trees- Very cool, but am note sure of its usability
Linear: Perspective Wall- Similar to the focus and content mechanism, FishEye systems. Effective Space Utilization
Spatial
Continuos Data
Unstructred

Question It seems that the Information Vizualizer is very effective for a small subset of problems, but is not so generalizable even though the paper claims that it is so. How would we use techniques described in the paper in our day-today work, considering the extreme ubiquity of the World Wide Web and the navigation and searching problems associated with it.