Information Visualization(Part 1)

cs3724: HCI

The Problem

Data

Human

Goal: Insight How?

Data Transfer

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!

Find the Red Square:

• Which state has highest Income?• Relationship between Income and Education?• Outliers?

Per Capita Income

Col

lege

Deg

ree

%

Scenarios = Data + Tasks

• Data categories:– Spatial (1,2,3D)– Multi-dimensional– Tree– Network– Text, documents

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!

DataMaps

• demo

Spotfire• Mapping data to graphics (x, y, size, color, shape…)

• Multiple views: brushing and linking• Dynamic

Queries• Details

window

Cars data

TableLens (Eureka by Inxight)

• Visual encoding of cell values• Details expand within context (fisheye)• Sorting

Cars data

Focus+Context• Hyperbolic Tree (star tree)

• Radial; shrink with distance to center• Drag to navigate

• Scalability?

• Xerox PARC, Inxight• http://startree.inxight.com/

Treemaps on the Web• Map of the Market: http://www.smartmoney.com/marketmap/• People Map: http://www.truepeers.com/ • Coffee Map: http://www.peets.com/tast/11/coffee_selector.asp

• “Squarified” TreeMap• http://www.research.microsoft.com/~masmith/all_map.jpg

SequoiaView• http://www.win.tue.nl/sequoiaview/• HW #3

Context is Important!

Information Visualization Mantra• Overview first, zoom and filter, then details on demand• Overview first, zoom and filter, then details on demand• Overview first, zoom and filter, then details on demand• Overview first, zoom and filter, then details on demand• Overview first, zoom and filter, then details on demand• Overview first, zoom and filter, then details on demand

What is Information Visualization?

The use of computer-supported,

interactive, visual representations

of abstract data to amplify cognition

My definition:

Show me the data!

Keys points

• Power of visual system• scenario = data + tasks• Mapping data to graphics & visual properties• Interaction for what doesn’t fit in visual rep.• Examples: multi-dimensional, tree• Mantra: Overview first• Choice of representation matters

What’s the Big Deal?

Presentation is everything!