1. Information Design and Visualization
Chris North
CS 3724: HCI

2. To do
Hall of Fame/Shame Presentations
Project: Requirements Analysis

3. Information scenarios
ANALYZE
analysis of
stakeholders,
field studies
claims about current
practice
Problem scenarios
DESIGN
Activity
scenarios
metaphors,
information
technology,
HCI theory,
guidelines
Functionality
iterative
analysis of
usability
claims and
re-design
Information scenarios
Look and feel
Interaction scenarios
PROTOTYPE & EVALUATE
summative
evaluation
formative
evaluation
Usability specifications

4. The Problem
Data
Human
Data Transfer
Goal: Insight
How?

5. Human Vision Highest bandwidth sense Fast, parallel
Pattern recognition
Pre-attentive
Extends memory and cognitive capacity
(Multiplication test)
People think visually
Impressive. Lets use it!

6. Find the Red Square:

8. Which state has highest Income?
Relationship between Income and Education?
Outliers?

9. College Degree %
Per Capita Income

10. Scenarios = Data + Tasks
Data categories:
Spatial (1,2,3D)
Tabular (Multi-dimensional)
Network, Tree
Text, documents
Combinations of categories

11. Visualization can do this!
User Tasks
Easy stuff: (1 or few items)
Min, max, average, %
Exact queries, known item search
Hard stuff:
Patterns, trends, distributions, changes over time,
outliers, exceptions,
relationships, correlations, multi-way,
combined min/max, tradeoffs,
clusters, groups, comparisons, context,
anomalies, data errors,
Paths, …
Excel can do this
Visualization can do this!

12. Examples of Tabular data visualization
DataMaps
Spotfire
TableLens

13. DataMaps
demo

14. Spotfire Mapping data to graphics (x, y, size, color, shape…)
Multiple views: brushing and linking
Dynamic Queries
Details window
Cars data

15. Visual Mapping: Step 1 Map: data items  visual marks Visual marks:
Points
Lines
Areas
Volumes
Glyphs

16. Visual Mapping: Step 2 Map: data items  visual marks
Map: data attributes  visual properties of marks
Visual properties of marks:
Position, x, y, z
Size, length, area, volume
Orientation, angle, slope
Color, gray scale, texture
Shape
Animation, time, blink, motion

17. Mapping Example in Spotfire
Film database
Film  dot
Year  x
Length  y
Popularity  size
Subject  color
Award?  shape

18. TableLens (Eureka by Inxight)
Visual encoding of cell values
Details expand within context (fisheye)
Sorting
Cars data

19. Examples of Tree data visualization
Windows Explorer
Star Tree
TreeMaps

20. Star Tree (Hyperbolic Tree)
Focus+Context
Radial; shrink with distance to center
Drag to navigate
Scalability?
Xerox PARC, Inxight

21. Treemaps Parent/child containment Size & color encoding
Map of the Market:
People Map:
Coffee Map:
U. Maryland

22. “Squarified” TreeMap

23. SequoiaView

25. Context is Important!

26. Information Visualization Mantra
Overview first, zoom and filter, then details on demand
- Ben Shneiderman

27. What is Information Visualization?
The use of computer-supported, interactive, visual representations of abstract data to amplify cognition

28. My definition:
Show me the data!

29. Keys points Power of visual system scenario = data + tasks
Mapping data to graphics & visual properties
2 steps
Interaction for what doesn’t fit in visual rep.
Dynamic queries, brushing, …
Examples: tabular data, trees
Mantra: Overview first…
Choice of visual representation matters

30. What’s the Big Deal?

31. Presentation is everything!
- Edward Tufte
Presentation is everything!

32. Project Step 3 – Design Due 3 weeks: get started early! Design space
Dimensions of the design space
Alternative designs
Claims analysis
Formative evaluation
Wizard of Oz
Refinements
Final design:
Scenarios
Representations

33. Homework #3 Due next Thurs Download KidPad software
Design a zoomable visualization