Displaying quantitative information
This presentation is the property of its rightful owner.
Sponsored Links
1 / 37

Displaying Quantitative Information PowerPoint PPT Presentation


  • 60 Views
  • Uploaded on
  • Presentation posted in: General

Displaying Quantitative Information. An exploration of Edward R. Tufte’s The Visual Display of Quantitative Information. Jeffrey Nichols Programming Usable Interfaces May 2, 2003. Good graphics. Napolean’s invasion of Russia, as drawn by Charles Joseph Minard (1781-1870).

Download Presentation

Displaying Quantitative Information

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Displaying Quantitative Information

An exploration of Edward R. Tufte’s

The Visual Display of Quantitative Information

Jeffrey Nichols

Programming Usable Interfaces

May 2, 2003


Good graphics

Napolean’s invasion of Russia, as drawn by Charles Joseph Minard (1781-1870)


More good graphics

The price of wheat compared to labour wages, William Playfair (1759-1823)


More good graphics

French train schedule, as drawn by E.J. Marey (1830-1904)


More good graphics

Map of the northern galactic hemisphere

(1.3 million galaxies shown)


What made these graphics good?


Bad graphics


More bad graphics


More bad graphics


More bad graphics


More bad USA Today Graphs


What made these graphics bad?


How can we make better graphics?

Tufte presents some principles of data graphics

  • Above all else, show the data.

  • Maximize the data-ink ratio

  • Erase non-data-ink

  • Erase redundant data-ink

  • Revise and edit


Above all else, show the data


Show the data


Data-Ink

  • Ink that changes as the data changes

  • Non-redundant ink!


Data-Ink Ratio

data-ink

Data-ink ratio =

Total ink used to print graphic

=Proportion of a graphic’s ink devoted to the non-redundant display of data-information.

=1.0 – proportion of graphic that can be erased without the loss of information


What is the data-ink ratio of this graphic?

Ratio of Histogram

< 0.05 !!!


Ratio of USA Today Graphic

  • What is the data-ink ratio of this graphic?

< 0.001


How can we make better graphics?

Tufte presents some principles of data graphics

  • Above all else, show the data.

  • Maximize the data-ink ratio

    • Within reason

    • Every bit of ink on a graphic requires a reason

  • Erase non-data-ink

  • Erase redundant data-ink

  • Revise and edit


How can we make better graphics?

Tufte presents some principles of data graphics

  • Above all else, show the data.

  • Maximize the data-ink ratio

  • Erase non-data-ink

  • Erase redundant data-ink

  • Revise and edit


Erase non-data-ink, within reason


Erase non-data-ink, within reason


Erase non-data-ink, within reason

11

5

2

1

0

18

7

Histogram of Midterm Results

# of Students

A-

B+

A

B

B-

C

Scoring Buckets


Erase redundant data-ink

11

5

2

1

0

18

7

Histogram of Midterm Results

# of Students

A-

B+

A

B

B-

C

Scoring Buckets


Erase redundant data-ink

18

11

5

2

1

0

7

Histogram of Midterm Results

What’s the data-ink ratio?

# of Students

A-

B+

A

B

B-

C

Scoring Buckets


How can we make better graphics?

Tufte presents some principles of data graphics

  • Above all else, show the data.

  • Maximize the data-ink ratio

  • Erase non-data-ink

  • Erase redundant data-ink

  • Revise and edit


The Principles Applied to Common Forms

Box Plots

Maximum

75%

Median

25%

Minimum


The Principles Applied to Common Forms

Box Plots

Maximum

75%

Median

25%

Minimum


The Principles Applied to Common Forms

Bar Graphs

Modified Graph

Original Graph


The Principles Applied to Common Forms

Scatter Plots

Modified Graph

Original Graph


The Principles Applied to Common Forms

Another Scatter Plot Variant


Conclusions

  • Show data variation, not design variation

  • Avoid using ink for non-data items

  • Avoid redundancy

  • Clear and detailed labeling should be used to defeat graphical distortion

  • Revise and Edit


Questions?


Thanks for a great class!

Reminder:

Final Exam on Friday, May 9th at 8:30am in this room


More Bad USA Today Graphs


Tufte’s Principles

  • Graphical Integrity

    • The representation of numbers, as physically measured on the surface of the graphic itself, should be directly proportional to the numerical quantities represented.

    • Clear, detailed, and thorough labeling should be used to defeat graphical distortion and ambiguity. Write out explanations of the data on the graphic itself. Label important events in the data.

    • Show data variation, not design variation.

    • In time-series displays of money, deflated and standardized units of monetary measurement are nearly always better than nominal units.

    • The number of information-carrying (variable) dimensions depicted should not exceed the number of dimensions in the data.

    • Graphics must not quote the data out of context.

  • Theory of Data Graphics

    • Above all else, show the data.

    • Maximize the data-ink ratio

    • Erase non-data-ink

    • Erase redundant data-ink

    • Revise and edit

  • Other comments

    • Graphical elegance is often found in simplicity of design and complexity of data

    • Data graphics are paragraphs about data and should be treated as such


  • Login