Information Visualizationfor E-content

David Modjeska

Assistant Professor

Faculty of Information Studies

University of Toronto

Information Highways 2002

Overview

1. Information Visualization and E-content

2. Research Project and Demo

3. Future Directions

1. Information Visualization

Online Information -Overview of Structure

• Difficult to get an overall sense of structure using textual representations. – Amount of online information increasing– Search engines provide access via queries– Directories such as Yahoo provide a

hierarchical view.

Information Visualization

• This decade, much interest in visualizing information structure. – Capitalizes on human skills for scanning visual

presentations quickly and efficiently. – Several algorithms and techniques– Little evaluative research for guidance in this

area.

Desktop 3D Environments

• Desktop 3D environments provide experience of navigating in a world on desktop computer – E.g., in a first-person action game.

– Can also represent information hierarchies, where concepts or items are represented as buildings or regions in model world.

– Potential application areas include the Web and information systems.

Interesting Research

• Info structure - spatial vs. semantic (Dillon et al.) • Info visualization (Card et al.; Chen)• IR Visualization (Chalmers et al.; Hemmje et al.) • “Focus+context” - cone tree, hyperbolic browser,

XML3D (Robertson et al., Lamping & Rao; Risden et al.)

• Wayfinding (Lynch; Passini; Darken & Sibert)• 3D info design (Waterworth; Vinson)

Document Landscape

Cone Tree (Vertical)

HyperbolicBrowswer

XML3D

Information Islands

Interesting Products

• Star Tree Viewer from Inxight

• File System Navigator from SGI

• VisualNet from Antarcti.ca

Star Tree Viewer from Inxight

•File System Navigator from SGI

VisualNet from Antarcti.ca

2. Research Project

Information SystemsDesign

UsabilityEvaluation

Software Engineering

InformationVisualization

Goals

• Develop new technique for visualizing hierarchical data in desktop 3D environments

• Investigate design trade-offs between spatial and semantic structure in visualizations

• Implement and empirically validate proposed visualization designs

• Explore prototypes’ implications for Web/intranet browsing with semantic structural overview

• Investigate value of 3rd dimension and role of spatial ability

Tools

• Created toolkit for prototyping desktop VR and hypertext visualization designs (1997-99)– input: data hierarchies in ASCII files (~ 1 MB each)

– filter: C++ software (~ 10,000 lines)

– output: virtual worlds in VRML files (~ 3 MB each)

• Developed tool to log user’s virtual navigation (Study 4)

• Acquired hierarchical data for user studies– filtered subset of Yahoo! Web index (1998)

– ~ 1500 info items on six levels

• Studies used SGI or PC workstation, fast graphics card, monitor, mouse, keyboard

“Efficient” Day World

Map View of “Efficient” Day World

(Demo)

Methods

• Conducted user study with 20 participants

• Compared two visualization designs

• During each study session:1) spatial ability test (a previous day)

2) Introduction and UI training (30 minutes)

3) 2 blocks of trials (20 minutes per block)a) “Scavenger hunt” for data items (0 -30 trials)

b) After each block, test for structure-learning ability

4) Questionnaire and debriefing

Results

• World design: in map design, users ...– overall - found more targets and rated higher efficiency– per trial - traveled less, made fewer errors, and stayed

closer to target

• Spatial ability: lowest 25% of users ...– overall - found fewer targets– per trial – traveled farther, and made more errors

• Structure-learning ability: higher-ability users ...– Overall - found more targets– per trial - stayed closer to target

• Benefits of 3D UIs for some tasks do not outweigh higher cognitive requirements.

• Different designs/training may be needed to compensate people with low levels of needed cognitive abilities

• Empirical evaluation is essential

Discussion

3. Implications and Future

General Implications

• Humans inherently 2+ D creatures, except for acrobats, divers, and pilots

• These studies showed value of 2D UI for task performance, but 3D for enjoyment

• Naïve naturalism in desktop VR bad for task and system performance

• Trade-off ease of sensory representation vs. power of imaginative construction

Product Implications

• Computer graphics evolution + younger market demographics + information explosion dynamic visual interfaces, tools to manage overload, and information as entertainment

• Visualization tools promising for intranets, digital libraries, e-business (B2C)

• Possibilities for real-time, multi-user communications (e.g., chat, conferencing) to add value and/or provide services

(Scenario)

Suggested Readings

• Card, S.K., Mackinlay, J.D., and Shneiderman, B., eds. Readings in information visualization: Using vision to think. Morgan Kaufmann, 1999.

• Gibson, W., Neuromancer. Ace Books, 1995.

• Modjeska, D. Hierarchical Data Visualization in Desktop Virtual Reality. Ph.D. thesis. University of Toronto, 2000. (www.dgp.utoronto.ca/people/modjeska/Pubs/modjeska_thesis.pdf)

• Stepenson, N., Snow Crash. Bantam, 2000