Informatie visualisatie: Les 4

Joris Klerkx - Erik Duval http://hci.cs.kuleuven.be joris.klerkx@cs.kuleuven.be

Human-Computer InteractionDept. ComputerwetenschappenKU Leuven

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Opdracht vorige week• Individueel (spreadsheet & infovis):

• Per team:

• Slides op blog

• Blogpost over wat je geleerd hebt uit feedback en voorstellen andere groepen

• Geïllustreerd scenario

• concreet

• verwerkte feedback

• 10 mins slot om te presenteren / 5 minuten feedback

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http://blog.ebemunk.com/a-visual-look-at-2-million-chess-games/

Human Perception

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Source: Katrien Verbert 5

Source: Katrien Verbert 6

A limited set of visual properties that are detected - very rapidly (< 200 to 250 ms), - accurately,- with little effort,- before focused attentionby the low-lever visual system on them.

Healey,C.,&Enns,J.(2012).A7en8onandVisualMemoryinVisualiza8onandComputerGraphics.IEEETransac*onsonVisualiza*onandComputerGraphics,18(7),1170-1188.

Pre-attentive characteristics

Note that eye movements take at least 200 ms to initiate.

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Pre-attentive characteristics

Find the red dot

<> Hue

Find the dot

<> shape

Find the red dot

conjunction not pre-attentive

http://www.csc.ncsu.edu/faculty/healey/PP/

helps to spot differences in multi-element display

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Pre-attentive characteristics

Line orientation Length, width Closure Size

Curvature Density, contrast Intersection 3D depth

Not all of them allow showing exact quantitative differencesHelps to spot differences in multi-element display

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http://www.csc.ncsu.edu/faculty/healey/PP/

Data

- structuretime, hierarchy, network, 1D, 2D, nD, …

- questions where, when, how often, …

- audience domain & visualisation expertise, …

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Questions (to get things going)

What is the average amount of students that bought the course book ?

What? When? How much? How often?

When did students start looking at the course material?

How much hours did Peter work on this assignment?

(Why did Peter have to redo his assignment?)

How often did Peter retake the course before he passed?

(why?)

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Visual mapping

Encode data characteristics into visual form

Each mark (point, line, area,…) represents a data element

Think about relationships between elements (position)

“Simplicity is the ultimate sophistication.”Leonardo da Vinci

J. Mackinlay. Automating the design of graphical presentations of relational information. ACM Transactions On Graphics, 5(2):110–141, 1986.

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• hue: categorical

• saturation: ordinal and quantitative

• luminance: ordinal and quantitative

How to choose colors

source from: Katrien Verbert 14

http://colorbrewer2.org

Position

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Position & color

http://time.com/12933/what-you-think-you-know-about-the-web-is-wrong/

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X4

How much bigger is the lower bar?

SlideadaptedfromMichaelPorath&KatrienVerbert

Length

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X5

How much bigger is the right circle?

SlideadaptedfromMichaelPorath&KatrienVerbert

Area

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Apparent magnitude curves

http://makingmaps.net/2007/08/28/perceptual-scaling-of-map-symbols

SlideadaptedfromMichaelPorath 20

Which one is more accurate?

SlideadaptedfromMichaelPorath 21

Compensating magnitude to match perception

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10 mins presentaties per groep!

Feedback / meedenken is belangrijk

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Tegen volgende week• Individueel:

• Spreadsheet

• infovis van de week:

• Relevante infovis (inhoud, techniek, etc) voor je eigen project. Wat leer je eruit?

• Per team:

• Slides online plaatsen

• Blogpost - wat geleerd uit feedback, hoe rekening houden ermee? prioritiseer en maak planning

• Implementatie / data verzamelen

• Show & Tell - feedback per groep

• Focus op vragen over de data & de inzichten die je hoopt te winnen

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