n August, the Columbia Accident Investigation Board at NASA released Volume 1 of its report on why the space shuttle crashed. As expected, the ship's foam insulation was the main cause of the disaster. But the board also fingered another unusual culprit: PowerPoint, Microsoft's well-known ''slideware'' program.

NASA, the board argued, had become too reliant on presenting complex information via PowerPoint, instead of by means of traditional ink-and-paper technical reports. When NASA engineers assessed possible wing damage during the mission, they presented the findings in a confusing PowerPoint slide -- so crammed with nested bullet points and irregular short forms that it was nearly impossible to untangle. ''It is easy to understand how a senior manager might read this PowerPoint slide and not realize that it addresses a life-threatening situation,'' the board sternly noted.

PowerPoint is the world's most popular tool for presenting information. There are 400 million copies in circulation, and almost no corporate decision takes place without it. But what if PowerPoint is actually making us stupider?

This year, Edward Tufte -- the famous theorist of information presentation -- made precisely that argument in a blistering screed called The Cognitive Style of PowerPoint. In his slim 28-page pamphlet, Tufte claimed that Microsoft's ubiquitous software forces people to mutilate data beyond comprehension. For example, the low resolution of a PowerPoint slide means that it usually contains only about 40 words, or barely eight seconds of reading. PowerPoint also encourages users to rely on bulleted lists, a ''faux analytical'' technique, Tufte wrote, that dodges the speaker's responsibility to tie his information together. And perhaps worst of all is how PowerPoint renders charts. Charts in newspapers like The Wall Street Journal contain up to 120 elements on average, allowing readers to compare large groupings of data. But, as Tufte found, PowerPoint users typically produce charts with only 12 elements. Ultimately, Tufte concluded, PowerPoint is infused with ''an attitude of commercialism that turns everything into a sales pitch.''

Microsoft officials, of course, beg to differ. Simon Marks, the product manager for PowerPoint, counters that Tufte is a fan of ''information density,'' shoving tons of data at an audience. You could do that with PowerPoint, he says, but it's a matter of choice. ''If people were told they were going to have to sit through an incredibly dense presentation,'' he adds, ''they wouldn't want it.'' And PowerPoint still has fans in the highest corridors of power: Colin Powell used a slideware presentation in February when he made his case to the United Nations that Iraq possessed weapons of mass destruction.

Of course, given that the weapons still haven't been found, maybe Tufte is onto something. Perhaps PowerPoint is uniquely suited to our modern age of obfuscation -- where manipulating facts is as important as presenting them clearly. If you have nothing to say, maybe you need just the right tool to help you not say it.

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