The usually admirable Edward Tufte, great guru of data visualization, succumbed, sad to say, to temptation. He published a well-publicized rant titled “The Cognitive Style of PowerPoint.” Like all rants it doesn’t really hold together, but since it assaults a source of shared annoyance, few who read it are likely to notice its faults.
For that, you need a professional fault-finder. Look no further.
A few weeks back, KJR provided some guidelines for improving PowerPoint presentations. According to Tufte I needn’t have bothered, because PowerPoint is irretrievably flawed. But what’s really flawed are his premises and conclusions. For example:
- PowerPoint has a “default cognitive style” characterized by “foreshortening of evidence and thought,” a “deeply hierarchical single-path structure,” and a “rapid temporal sequencing of thin information rather than focused spatial analysis.”To the extent that “default cognitive style” and “foreshortening of evidence and thought” mean anything in particular, it’s probably that speeches don’t lend themselves to nuance.
As for the “deeply hierarchical single-path structure,” and “rapid temporal sequencing” … now this is just an opinion: Presentations should have a beginning, middle, and end — a logical narrative sequence that makes absorbing the presenter’s evidence and logic as easy as possible — and be fast-paced enough to avoid boring the audience to death. They aren’t conversations, any more than novels are conversations. Speeches should be temporally sequenced. The alternative is foggy confusion.
- “PowerPoint slides projected on a wall are very low resolution — compared to paper, 35mm slides, and the immensely greater capacities of the human eye-brain system.”This is an excellent example of a half truth. Computer displays projected on a wall are, right now, lower in resolution than 35mm slides. So are digital cameras. It’s the hardware, not the software.
PowerPoint’s resolution is exactly the same as that of the software Tufte used to write and publish “The Cognitive Style of PowerPoint.” If it weren’t, audiences wouldn’t have the opportunity to complain about the use of small fonts … which, by the way, they would also complain about were they projected from 35mm slides. The human eye-brain system is limited to 20/20 vision unless aided by binoculars. PowerPoint has nothing at all to do with this.
- Impoverished space leads to over-generalizations, imprecise statements, slogans, lightweight evidence, abrupt and thinly-argued claims.Well of course it does. For the same reason, Keep the Joint Running, which I limit each week to about 800 words, can’t contain as much evidence, detailed logic, or other forms of information as the Encyclopedia Britannica.
This is neither profound nor damning: The same logic suggests we should criticize Shakespeare for having written sonnets, because the length and format precludes the inclusion of (for example) detailed multi-page comparison charts.
A projected PowerPoint slide, which must be read by a thousand people in an auditorium, can’t include as much information as a PowerPoint slide that’s printed, packaged in a binder, and distributed in a boardroom meeting. So what?
- “Bullet outlines dilute thought.”According to Tufte, PowerPoint’s impoverished resolution coerces slide-makers into using bulleted lists. He complains that “… sometimes the bullet hierarchies are so complex and intensely nested that they resemble computer code.”
He also complains that they present superficial thinking, leaving unanswered this question: How can information that’s so complex and intensely nested that it resembles computer code be contained in a format whose resolution is impoverished, and be described as superficial?
Tufte works hard to show that the fault lies in PowerPoint itself and not in its misuse. As an example of his contorted “logic,” he presents a chart titled “The Table of Causalities,” part of John Graunt’s Bills of Mortality, published in 1662, that contains 82 rows and 30 columns. Tufte claims PowerPoint’s inherently low resolution prevents it from handling this table.
Well, kinda: PowerPoint does impose a 25×25 limit, but you can easily build an 82×30 table in MS Word and paste it into PowerPoint. It wouldn’t, of course, project very well, but that’s inherent in the nature of making speeches. As proof, imagine projecting the same table on a 35mm slide, or just reciting it. Even hand gestures would be of little help.
Had Tufte pointed out that a lot of business “logic” is specious, I’d have agreed in a heartbeat. Had he explained that PowerPoint is often used as a crutch, I’d be applauding. Had he suggested that too often, business managers present when they should converse, or that PowerPoint should be a choice rather than the default, I’d have nothing to add beyond my heartfelt gratitude.
He didn’t. He went on a rant, and rants have even less information than the average PowerPoint presentation.
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My thanks to Warren Young for providing a copy of Tufte’s treatise for me to review.