Edward Tufte is a giant in the field of data visualization, and he laid out the groundwork for many of the ideas for effective visual representation of data. A Yale statistician, he now mostly works on his sculptures (he has a studio in Chelsea in New York), and gives talks around the country.
Some ideas worth pulling out from Tufte:
“Gratuitous decoration and reinforcement of the data generates redundant data-ink”
5 principles of data-to-ink ratio
1. above all else, show the data
2. maximize the data-ink ratio
3. erase non-data ink
4. erase redundant data-ink
5. revise and edit
Successful displays of statistical information:
1. have a properly chosen format and design
2. use words, numbers, and drawing together
3. reflect a balance, a proportion, a sense of relevant scale
4. display an accessible complexity of detail
5. often have a narrative quality, a story to tell about the data
6. are drawn in a professional manner, with the technical details of production done with care
7. avoid content-free decoration, including chartjunk.
“It is nearly always helpful to write little messages on the plotting field to explain the data, to label outliers and interesting data points, to write equations and sometimes tables on the graphic itself, and to integrate the caption and legend into the design so that the eye is not required to dart back and forth between textual material and the graphic.”….meaning, direct labeling, where possible.
- Induce the reader to think about substance (content, information) rather than form or color or design — too much “chart junk” and visual extravaganza distracts rather than focuses the reader’s/viewer’s attention
- Encourage the eye to compare different pieces of data
- Reveal the data at several levels of detail
- Avoid distortion
- The representation of numbers, as physically measured on the surface of the graph itself, should be directly proportional to the numerical quantities represented.
- Labeling should be clear, detailed, precise, and thorough.
- The number of information-carrying (variable) dimensions depicted should not exceed the number of dimensions in the data. (compare to Illinsky’s redundant encoding)
- Graphics must not use data out of context.
Criticisms of Tufte’s minimalist approach to information design:
Canadian study of Tufte’s chart junk rule (http://dmrussell.net/CHI2010/docs/p2573.pdf)
Inbar’s study on data-ink rule (PDF is not free but available, http://dl.acm.org/citation.cfm?id=1362587)