Visualizationmnovotny/_nais/files/viscom2013/viscom_10.pdf · Also called visualization •...

Visualization

What’s the point at all?

Graphical systems, visualization and multimedia 2

What is visualization?

Business graphics 3

Ordinary” computer graphics

• Show things we know

• Most realistic way

Visualization

• Show things we don’t know (yet)

• Most understandable way

Also called visualization

• Rendering of architectural models

• Not our topic today

Business graphics 4

www.designteam.sk

So what is visualization?

• Giving to data a graphical form that is

different from their original form.

• Often the data has no geometry / graphical

form itself

• Sometimes it does and we want a different

form

• That is visualization

Business graphics 5

Success story

Dr. John Snow (1813-1858)

Business graphics 6

Success story

Business graphics 7

Benefits of visualization

John Snow Pub (near former Broad Street)

Business graphics 8

Failure story

Challenger space shuttle ( 28/01/1986 )

Business graphics 9

O-Ring failure probability

Business graphics 10

Purposes of visualization

• Exploration

– “Discover the unexpected”

• Confirmation

– “Detect the expected”

• Presentation

– Communicate knowledge


Types of visualization

• Medical visualization

• Scientific visualization

• Information visualization

• Info graphics


Some basic visual attributes

• Length

• Area, Volume

• Color

• Angle

• Connectivity

• Hierarchy


Length

• Can’t perceive

absolute value

– only relative

• Compare to

seen items

• Compare to

scale


Area, volume

• Perceived as

quadratic (x2) - area

cubic (x3) – volume

• Advantage when

displaying very wide

range of values

(e.g. 1:100:10000)


Color in visualization

• Visible light = infinite number of colors

• Monitor = ~millions of colors

• Our perception = ?


Colors for categories

• Category distinction

– Limited number (<10 preattentively)



Colors for sequential values

• Categorical colors

• Sequential colors


Sequential vs. diverging

• Ordinal rather than categorical values

• Only few distinct levels.

Continuous values will not be read properly.

sequential diverging


Color scales

• For categories

– Qualitative color schemes

• For ordinal values

– Sequential color schemes

– Diverging color schemes

• For small number of values

– Can be increased e.g. by using texture

Connectivity, orientation

• Remember gestalt laws (connectivity)

• Orientation (arrows, gravity)


Relationships

TheyRule.net

Ratios and volume

Angles are risky

• Our angle perception is very bad

• Find the 3 largest, is sum of blue > 50%?


Stephen Few

Save the Pies for Dessert

Perspective/3D is risky


Hierarchy, insetting


http://www.smartmoney.com/marketmap/

Hierarchy, insetting


http://www.nytimes.com/interactive/2008/05/03/business/20080403_SPENDING_GRAPHIC.html

Hierarchy, outsetting


Infographics


What’s important

• Aesthetics is important but should not come

in way of readability

• Consistency – if you establish a visual

language, stick to it in the whole picture

• Chart junk still matters

• Infographics should:

– Be designed by infovis people.

Then decorated by artists

– Not be designed by artists only

– Neither by programmers only

This is far from infographics

• What’s the use?

• Is the visual

language

consistent?

• Absorption

reduction is

shown in the

same way as

direct effectshttp://coliccalm.com/PPI-infographic/

Even farther

Putting text next to pictures is not infographics.

Whatever cute pictures you use

http://www.thelunchtray.com/infographic-on-food-advertising-and-childhood-obesity/

Art over info

See visibledata.info for this and more disasters

Math over info

Number precision? Why are some highlighted?

Text over graphics

www.sme.sk/infografika

Psychology matters

Robert Kosara: The Bikini Chart http://eagereyes.org/blog/2012/bikini-chart

Psychology matters


Don’t make basic mistakes


And of course…

• Consider the meaning of the data


Examples on the

popular principles

(and mistakes)

in information graphics

Quadratic area perception

• Large

values

displayed

by area,

not length

• Any

improve-

ments?

www.h1.cz

Quadratic area perception

www.shoptet.cz

2.2 px2.6 px

2.4 px

5.3 px 7 px

For fonts also!

• More quadratic non-sense

www.shoptet.cz

37 px

13 px

Communicating probability

http://www.nytimes.com/interactive/2012/11/02/us/politics/paths-to-the-white-house.html

Questionable language

• The first instinct is

to compare the

differently colored

areas

• It seems to work

in the first image

• But what about

the second?

• Remember: PEOPLE DON’T READ!

http://www.huffingtonpost.com/2012/11/04/hurricane-sandy-vs-katrina-infographic_n_2072432.html

Using glyphs

http://www.university-autonomy.eu/

Organizational - executive head, governing bodies, legal entities

Financial - type of funding, borrow money, create surplus, tuition fees

Academic - student numbers, admissions, programs, languages

Staffing - recruitment, salaries, dismissal, promotion

Temporal data / interactive

http://www.guardian.co.uk/uk/interactive/2011/dec/07/london-riots-twitter

Temporal data / passive

Baby Name Voyager


Absolute vs. relative values

Which one is better then?

More sources:

• http://www.coolinfographics.com

• http://visual.ly

• http://infosthetics.com

• http://visualization.geblogs.com

• http://www.visual-literacy.org

• http://junkcharts.typepad.com/

• Tools:

– http://selection.datavisualization.ch

U.S. federal spending


Deadliest drugs (or?)

Everything OK?

Deadliest drugs (or?)


Lying/errors in visualization

• 100m record

evolution

9,6

9,7

9,8

9,9

10

10,1

10,2

10,3

10,4

10,5

10,6

10,7

1900 1920 1940 1960 1980 2000 2020

Lying/errors in visualization


How to lie with visualization


Bar chart gone wild


Benefits of visualization

• Image is perceived faster than text

• Language independence

• Better perception of data

• (psssst…. A way to lie improve reality)

• Find errors in data

• Gain new insights into the data

Detect the expected, discover the unexpected


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