The Master of Diagrams: Edward Tufte
August 29, 2010 § Leave a comment
Edward Tufte is an American statistician and professor emeritus of political science, statistics, and computer science at Yale University. He is noted for his writings on information design; Tufte is an expert in the presentation of informational graphics such as charts and diagrams.
Tufte’s writing is important in such fields as information design and visual literacy, which deal with the visual communication of information. He coined the term “chartjunk” to refer to useless, non-informative, or information-obscuring elements of quantitative information displays.
He uses the term “data-ink ratio” to argue against using excessive decoration in visual displays of quantitative information. In his book Visual Display, Tufte states:
Sometimes decorations can help editorialize about the substance of the graphic. But it’s wrong to distort the data measures—the ink locating values of numbers—in order to make an editorial comment or fit a decorative scheme.
Tufte also encourages the use of data-rich illustrations with all the available data presented. When examined closely, every data point has value; when seen overall, trends and patterns can be observed. Tufte suggests these macro/micro readings be presented in the space of an eyespan, in the high resolution format of the printed page, and at the unhurried pace of the viewer’s leisure. Tufte uses several historical examples to make his case including John Snow’s cholera outbreak map, Charles Joseph Minard’s Carte Figurative, early space debris plots, and Maya Lin’s Vietnam Veterans Memorial. For instance, the listing of the names of deceased soldiers on the black granite of Lin’s sculptural memorial is shown to be more powerful as a chronological rather than as an alphabetical list. The sacrifice each individual made is thus highlighted within the overall scope of the war.
Criticism of PowerPoint
Tufte has criticized the way Microsoft PowerPoint is typically used. In his essay “The Cognitive Style of PowerPoint”, Tufte criticizes many properties and uses of the software:
It is used to guide and to reassure a presenter, rather than to enlighten the audience;
It has unhelpfully simplistic tables and charts, resulting from the low resolution of early computer displays;
The outliner causes ideas to be arranged in an unnecessarily deep hierarchy, itself subverted by the need to restate the hierarchy on each slide;
Enforcement of the audience’s linear progression through that hierarchy (whereas with handouts, readers could browse and relate items at their leisure);
Poor typography and chart layout, from presenters who are poor designers and who use poorly designed templates and default settings (in particular, difficulty in using scientific notation);
Simplistic thinking, from ideas being squashed into bulleted lists, and stories with beginning, middle, and end being turned into a collection of disparate, loosely disguised points. This may present an image of objectivity and neutrality that people associate with science, technology, and “bullet points”.
Tufte’s criticism of PowerPoint has extended to its use by NASA engineers in the events leading to the Columbia disaster. Tufte’s analysis of a representative NASA PowerPoint slide is included in a full-page sidebar entitled “Engineering by Viewgraphs”  in Volume 1 (page 191) of the Columbia Accident Investigation Board’s report.
Tufte argues that the most effective way of presenting information in a technical setting, such as an academic seminar or a meeting of industry experts, is by distributing a brief written report that can be read by all participants in the first 5 to 10 minutes of the meeting. Tufte believes that this is the most efficient method of transferring knowledge from the presenter to the audience. The rest of the meeting is then devoted to discussion and debate.
One method Tufte encourages to allow quick visual comparison of multiple series is the Small multiple. A chart with many series shown on a single pair of axes can often be easier to read when displayed as several separate pairs of axes placed next to each other. This is particularly helpful when the series are measured on quite different scales, but over the same range on the x-axis (usually time).