Tuftes Design Principles

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Tuftes Design Principles

• CS 7450 - Information Visualization
• January 29, 2002
• John Stasko

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HW 2 - Minivan Data Vis

• What people did
• Classes of solutions
• Data aggregation, transformation
• Tasks - particular versus types

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Envisioning Information

• Lets hear your views on the book...

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Graphical Excellence

• Principles
• Graphical excellence is the well-designed
  presentation of interesting data---a matter of
  substance, of statistics, and of design.
• Graphical excellence consists of complex ideas
  communicated with clarity, precision and
  efficiency.

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Graphical Excellence

• Principles
• Graphical excellence is that which gives to the
  viewer the greatest number of ideas in the
  shortest time with the least ink in the smallest
  space
• Graphical excellence is nearly always
  multivariate.
• And graphical excellence requires telling the
  truth about the data.

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Leveraging Human Capabilities

• Data graphics should complement what humans do
  well
• Quote from top of Vol.2, page 50

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Summary

• 1. Tell the truth
• Graphical integrity
• 2. Do it effectively with clarity, precision
• Design aesthetics

Lets look at each of these
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1. Graphical Integrity

• Your graphic should tell the truth about your data

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Example
Stock market crash?
500
475
450
2002
2001
2000
1999
1998
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Example
500
250
Show entire scale
0
2002
2001
2000
1999
1998
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Example
500
250
Show in context
0
2000
1990
1980
1970
1960
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Chart Integrity

• Wheres baseline?
• Whats scale?
• Whats context?

Examples Vol. 1, page 54 (wheres 0?)
Vol. 1, page 54 (whats component?)
Vol. 1, page 57 (change scale)
Vol. 1, page 61 (change scale)
Vol. 1, page 74 (show context)
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Watch Size Coding

• Height/width vs. area vs. volume

Examples Vol. 1, page 69 (area)
Vol. 1, page 62 (volume) Vol.
1, page 61 (change scale) Vol.
1, page 74 (show context)
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Measuring Misrepresentation

• Visual attribute value should be directly
  proportional to data attribute value

Size of effect shown in graphic Size of effect in
data
Lie factor
4280 454
9.4
p.62
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2. Design Aesthetics

• Set of principles to help guide designers

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Design Principles

• Maximize data-ink ratio

Data ink
Data ink ratio
Total ink used in graphic
proportion of graphics ink devoted to the
non-redundant display of data-information
Examples Vol.1, page 94 (good and bad)
Vol.1, page 30 (NYC weather, 2220 numbers)
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More...

• Above all else, show the data
• Maximize the data-ink ratio
• Erase non-data-ink
• Erase redundant data-ink
• Revise and edit

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More...

• Maximize data density

number of entries in data matrix
data density of graphic
area of data graphic
Quote from bottom of Vol. 1, page 168
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Redesign charts

• Bar chart, scatter plot, box plot(See drawings)

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Design Principles

• Avoid chartjunk
• Extraneous visual elements that detract from
  message
• Great narrative Vol.2, bottom page 33-34

Examples Vol.1, page 108 (shimmering display)
Vol.2, page 34 (diamonds are a
girls)
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Design Principles

• Utilize multifunctioning graphical elements
  (macro/micro readings)
• Graphical elements that convey data information
  and a design function

Examples Vol. 1, page 140-1 (bar charts)
Vol.2, pages 36-7 (city maps)
Vol. 2, page 42-44 (Viet Nam Memorial)
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Design Principles

• Use small multiples
• Repeat visually similar graphical elements nearby
  rather than spreading far apart

Examples Vol. 1, pages 170- 174
Consumer Reports
Vol.2, pages 68-69 (trolley cars
calligraphy)
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Design Principles

• Show mechanism, process, dynamics, and causality
• Cause and effect are key
• Make graphic exhibit causality

Examples Vol.3, pages 38-53 (space shuttle)
Vol.3, page 144 (fall in river)
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Design Principles

• Escape flatland
• Data is multivariate
• Doesnt necessarily mean 3D projection

Examples Vol.2, page 12 (Japan guide)
Vol.2, page 24 (Java railroad)
Vol.3, pages 90-91 (history of music)
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Design Principles

• Utilize layering and separation
• 11 3 or more
• Good or bad

Examples Vol.2, page 54 (copier assembly)
Vol.2, pages 61-2 (11 3)
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Design Principles

• Utilize narratives of space and time
• Tell a story of position and chronology through
  visual elements

Examples Vol.1, page 43 Vol.2, page 110 (life
of beetle) Vol.2, pages 102-103
(air flight schedules)
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Design Principles

• Content is king
• Quality, relevance and integrity of the content
  is fundamental
• Whats the analysis task? Make the visual design
  reflect that
• Integrate text, chart, graphic, map into a
  coherent narrative

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Graph and Chart Tips

• Avoid separate legends and keys -- Just have that
  information in the graphic
• Make grids, labeling, etc., very faint so that
  they recede into background

Examples Vol. 2, page 54, 63 Vol.
3, page 74
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Using Color Effectively

• The often scant benefits derived from coloring
  data indicate that even putting a good color in a
  good place is a complex matter. Indeed, so
  difficult and subtle that avoiding catastrophe
  becomes the first principle in bringing color to
  information Above all, do no harm.

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Proper Color Use

• To label
• To measure
• To represent or imitate reality
• To enliven or decorate

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Color Examples

• Good
• Vol.2, page 80Swiss mtn map
• Vol.2, page 91 orVol.3, page 76Japan sea
  map(Bad on Vol.3, page 77)

• Bad
• Vol.1, page 153US rate mapGreat description
• Vol.2, page 82US rate map
• Vol.2, page 88Computer screensGreat quote

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Guides for Enhancing Visual Quality

• Attractive displays of statistical info
• have a properly chosen format and design
• use words, numbers and drawing together
• reflect a balance, a proportion, a sense of
  relevant scale
• display an accessible complexity of detail
• often have a narrative quality, a story to tell
  about the data
• are drawn in a professional manner, with the
  technical details of production done with care
• avoid content-free decoration, including chartjunk

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Information Overload

• Text from top of Vol.2, page 51
• Clutter and confusion are failures of visual
  design, not attributes of information.

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Minard graphic
size of army direction
latitude longitude
temperature date
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Graphical Displays Should

• Show the data
• Induce the viewer to think about substance rather
  than about methodology, graphic design the
  technology of graphic production, or something
  else
• Avoid distorting what the data have to say
• Present many numbers in a small space
• Make large data sets coherent
• Encourage the eye to compare different pieces of
  data

• Reveal the data at several levels of detail, from
  a broad overview to the fine structure
• Serve a reasonably clear purpose description,
  exploration, tabulation, or decoration
• Be closely integrated with statistical and verbal
  descriptions of a data set

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Sources Used
E. Tufte, The Visual Display of Quantitative
Information E. Tufte, Envisioning Information E.
Tufte, Visual Explanations
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Upcoming

• Interaction and Dynamic Queries
• 2 days
• IV Systems assignment due in a week