•House directions Exercise CS 7450 -Information VisualizationJan. 8, 2004John Stasko Introduction

Introduction

CS 7450 - Information Visualization Jan. 8, 2004

John Stasko

Exercise

• House directions

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Data Explosion

• Society is more complex

−There simply is more “stuff”

• Computers, internet and web give people access to an incredible amount of data

−news, sports, financial, purchases, etc...

How much data?

• Between 1 and 2 exabytes of unique info produced per year

−1000000000000000000 (10¹⁸⁾ bytes

−250 meg for every man, woman and child

−Printed documents only .003% of total

Peter Lyman and Hal Varian, 2000

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Data Overload

• Confound: How to make use of the data

−How do we make sense of the data?

−How do we harness this data in decision- making processes?

−How do we avoid being overwhelmed?

The Need is There

In five years, 100 million people will be using an information-visualization tool on a near-daily basis. And products that have

visualization as one of their top three features will earn $1 billion per year. -- Ramana Rao, founder and chief

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The Problem

Data

How?

Data Transfer Web,

Books, Papers, Game scores, Scientific data, Biotech, Shopping People Stock/finance

News Vision: 100 MB/s

Ears: <100 b/s Telepathy Haptic/tactile Smell

Taste

Two slides courtesy of Chris North

Human Vision

• Highest bandwidth sense

• Fast, parallel

• Pattern recognition

• Pre-attentive

• Extends memory and cognitive capacity

(Multiplication test)

• People think visually

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The Challenge

• Transform the data into

(understanding, insight) thus making it useful to people

Example

Which state has the highest income?

Is there a relationship between income and education?

Are there any outliers?

Questions:

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Visualize the Data

Per Capita Income

College Degree %

Even Tougher?

• What if you could only see 1 state’s data at a time?

• What if I read the data to you?

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Illustrates Our Approach

• Provide tools that present data in a way to help people understand and gain insight from it

• Cliches

−“Seeing is believing”

−“A picture is worth a thousand words”

Exercise Redux

• An interesting query…

• People work differently

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Visualization

• Often thought of as process of making a graphic or an image

• Really is a cognitive process

−Form a mental image of something

−Internalize an understanding

• “The purpose of visualization is insight, not pictures”

−Insight: discovery, decision making, explanation

Main Idea

• Visuals help us think

−Provide a frame of reference, a temporary storage area

• External cognition

−Role of external world in thinking and reason

−Examples?

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Information Visualization

• What is “information”?

−Items, entities, things which do not have a direct physical correspondence

−Notion of abstractness of the entities is important too

−Examples: baseball statistics, stock trends, connections between criminals, car

attributes...

Information Visualization

• What is “visualization”?

−The use of computer-supported, interactive visual representations of data to amplify cognition.

From [Card, Mackinlay Shneiderman ‘98]

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What It’s Not

• Scientific Visualization

−Primarily relates to and represents something physical or geometric

−Examples

Air flow over a wing Stresses on a girder

Weather over Pennsylvania

Information Visualization

• Components:

−Taking items without a direct physical

correspondence and mapping them to a 2-D or 3-D physical space.

−Giving information a visual representation that is useful for analysis and decision-making

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Two Key Attributes

• Scale

−Challenge often arises when data sets become very large

• Interactivity

−Want to show multiple different perspectives on the data

Domains for Info Vis

• Text

• Statistics

• Financial/business data

• Internet information

• Software

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Chapters 1 and 2

• Discuss

• Interesting?

• Thought-provoking?

• Agree/Disagree?

Examples

• Images

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Excel

No, Virginia, that’s not an InfoVis

And get rid of those darn 3D bars!

USA Today Graphics

Or worse yet…

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Minivan Data

Bullet Train Schedule

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Atlanta Flight Traffic

Atlanta Journal April 30, 2000

In Living

Color

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2000 Election Ballot

Electoral College

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The Comics

Understanding Comics by Scott McCloud

Hartsfield Airport

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Unemployment Rates

Power Costs

Average cost per month to use

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London Subway

True Geography

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Napolean’s March

size of army

direction latitude

longitude temperature date

From E. Tufte

The Visual Display of Quantitative Information

Minard graphic

NYC Weather

2220 numbers

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Examples

• Software

Map of the Market

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NY Timeformations

www.skyscraper.org/timeformations

Transparent New York

Philip Glass Music

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StarTree

www.inxight.com Hyperbolic tree

SunBurst

File browser

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HomeFinder

HCIL

Univ. Maryland

Tasks in Info Vis

• Search

−Finding a specific piece of information

How many games did the Braves win in 1995?

What novels did Ian Fleming author?

• Browsing

−Look over or inspect something in a more casual manner, seek interesting information

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Tasks in Info Vis

• Analysis

−Comparison-Difference

−Outliers, Extremes

−Patterns

• Assimilation

• Monitoring

• Awareness

Segue to next class…

Upcoming

• User (cognitive) tasks

−Reading:

Chapter 6 Zhou & Feiner

• Multivariate data sets

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Sources Used

• CMS book

• Spence book