Lies, Damned Lies and the Use of PowerPoint

One of my favourite texts during my undergraduate studies was a small book entitled Lies, Damned Lies and Statistics—based on a phrase originally attributed to Mark Twain.

Lies, Damned Lies and Statistics

He coined it to bring attention to the use of statistics to bolster weak arguments. And it never ceases to amaze me that, more than a century later, the more things change, the more they stay the same—especially when it comes to the use of PowerPoint in presentations.

Consider an article I recently encountered entitled “Using visuals effectively in PowerPoint Presentations.”

The author tells us “visuals increase the impact of your PowerPoint presentation” and we should “check the information retention grid” (i.e. the chart below). The implication, of course, is that if we use PowerPoint during presentations, our audiences will have greater retention of our information.

Is that a lie? A damned lie? Or a statistic?

Well, you be the judge. The article was based on a 1996 article posted on the US Department of Labor website, written to help people design effective presentations. Interestingly, if you compared most modern, PowerPoint-driven presentations to the article’s section on “Tips on Preparing Visual Aids,” they would fail miserably. There is some great advice in this 17-year-old article, including:

  • Start with at least a rough outline of the goal and major points of the presentation before selecting the visual aid(s)—(i.e. develop your content first!).


  • Each element of an audio-visual product—a single slide or a page of a flip chart, for example— must be simple and contain only one message.
  • Keep visual aids BRIEF.
  • Ask the audience to read or listen, not both; visual aids should not provide reading material while you talk.

Most importantly, the article does not mention PowerPoint once. It talks about the strengths and weaknesses of a variety of visual tools—flip charts, overhead transparencies, posters, 35-mm slides, audio-slide shows and videotape—making the chart here completely irrelevant to any discussion of the use of PowerPoint.

In summary, this interesting article provides three insights we’ve forgotten in our mad rush to make every presentation a PowerPoint presentation.

First, content should be developed, then visual aids selected. Second, audiences cannot read and listen at the same time. Third, there are a variety of visual aids that could used, not just PowerPoint (or, in the article’s vernacular, 35-mm slides).

And that’s what Mark Twain was talking about—making a completely illogical leap from one statistic to a whole new set of assumptions.

(For those interested in “untangling numbers from the media, politicians and activists,” Lies, Damned Lies and Statistics is available from Google Books.)