THE COGNITIVE STYLE OF POWERPOINT
Edward R. Tufte
Graphics press LLC, 2003, 27 pp. ISBN 0-9613921-5-0 www.edwardtufte.com
Edward Tufte is a former professor of statistics and analytical design at Yale. He writes, designs and publishes his own books on analytical design. This essay is a scathing critique of PowerPoint. “Some methods of presentation are better than others. And PowerPoint is rarely a good method.” (26) Using farcical slides as well as real-life examples, he illustrates how PowerPoint weakens presentations of scientific data, risk assessment, and strategic planning.
Slides often reduce the analytical quality of presentations. The ready-made designs usually weaken verbal and spatial reasoning and almost always corrupt statistical analysis. (3)
“PowerPoint is entirely presenter-oriented, and not content-oriented, not audience-oriented.” The cognitive style of standard default templates is faulty. It results in “foreshortening evidence and thought, low spatial resolution, a deeply hierarchical single path structure as the model for organizing every type of content, breaking up narrative and data into slides and minimal fragments, rapid temporal sequencing of thin information rather than focused spatial analysis, conspicuous decoration and Phluff, a preoccupation with format not content, an attitude of commercialism that turns everything into a sales pitch.” (4)
“Many true statements are too long to fit on a PP slide, but this does not mean we should abbreviate the truth to make the words fit. It means we should find a better way to make presentations.” (4) A slide says “Correlation is not causation.” This is misleading in that while correlation does not prove causation, it is a necessary condition and a good hint.
Bullet lists leave critical relationships unspecified. They communicate only sequence, priority or membership in a set. They ignore and conceal the causal assumptions and analytic structure of the reasoning. Sentences with subjects and verbs are usually better. (5-6)
Tufte shows three PowerPoint presentations used by NASA officials to report the in-flight risk assessment of the damage to the ill-fated Challenger. His critique of the over-optimistic assessment is crushing. The reports used standard PP formats with bullet outlines, segregation of words and numbers, cryptic typography, etc.
The PowerPoint information hierarchy mimicked the hierarchical structure of the bureaucracy that produced it. “The choice of headings, arrangement of information, and size of bullets on the key chart served to highlight what management already believed.” (10)
“PowerPoint will not do for serious presentations. Serious problems require serious tools.” (11)
A picture can communicate much more than a thousands words and much more quickly. However, “nearly all PowerPoint slides that accompany talks have much lower rates of information transmission than the talk itself. Too often the images are content-free clip art, the statistical graphics don’t show data, and the text is grossly impoverished.” “The PowerPoint slide typically shows 40 words, which is about 8 seconds-worth of silent reading material.” (12)
“A vicious circle results. Thin content leads to boring presentations. To make them unboring, PPPhluff is added, damaging the content, making the presentation even more boring....” For serious presentations replace slides with handouts showing words, numbers, data graphics and images together. “Thin visual content prompts suspicions: ‘What are they leaving out? Is that all they know? Does the speaker think we’re stupid?’ ‘What are they hiding?’” (12)
The metaphor behind the PP cognitive style is the software corporation and program writing “(deeply hierarchical, nested, highly structured, relentlessly sequential, one-short-line-at-a-time) and marketing (fast pace, misdirection, advocacy not analysis, slogan thinking, branding, exaggerated claims, marketplace ethics).” (13)
A better metaphor for presentations is good teaching, exhibiting the core ideas of “explanation, reasoning, finding things out, questioning, content, evidence, credible authority not patronizing authoritarianism....” (13)
The actual text of the Gettysburg Address is set next to six hilarious PowerPoint slides representing it. My favorite is the chart showing in two columns the number of new nations: -87 years, 1; now, 0. (You know, “Four score and seven years ago...”)
The use of PowerPoint with medical data and statistical information is critiqued on pp. 16-21.
“The PP slide format has probably the worst signal/noise ration of any known method of communication on paper or computer screen.” (22)
“Sometimes quick chunks of thin data may be useful (flash-card memorizing), other times not (comparisons, links, explanations). But formats, sequencing, and cognitive approach should be decided by the character of the content and what is to be explained, not by the limitations of the presentation technology.” (23)
“Presentations largely stand or fall depending on the quality, relevance, and integrity of the content. The way to make big improvements in a presentation is to get better content.” (24) [However, we all know that presentation skills are also very important. Dlm]
“Audience boredom is usually a content failure, not a decoration failure. At a minimum, a presentation format should do no harm to content.” (24)
“The practical conclusions are clear. PowerPoint is a competent slide manager and projector for low-resolution materials. And that’s about it.” (24)
“Never use PP templates for arraying words or numbers. Avoid elaborate hierarchies of bullet lists. Never read aloud from slides. Never use PP templates to format paper reports or web screens. Use PP as a projector for showing low-resolution color images, graphics, and videos that cannot be reproduced as printed handouts at a presentation.” “Thoughtfully planned handouts at your talk tell the audience that you are serious and precise; that you seek to leave traces and have consequences. And that you respect your audience.” (24)
“PP has a distinctive, definite, well-enforced, and widely-practiced cognitive style that is contrary to serious thinking. PP actively facilitates the making of lightweight presentations.” (26)