Philip Greenspun points out an essay by Edward Tufte called “The Cognitive Style of PowerPoint” about the particular choices in organization and style of presentation and their detrimental effects on communication. The essay is only available in hardcopy for sale, but on his website he analyses a PowerPoint slide that played a key role in downplaying the risk to the shuttle from the falling foam debris.
As one who admittedly uses PowerPoint and slides in general as a crutch, I think he’s right that it and other
slideware programs have changed the way people give presentations, but I’m not sure things are nearly as bad Greenspun makes it out to be…
I’m convinced that PowerPoint has changed the way people prepare and give talks, even people who shun all things MicroSoft. I’ve especially noticed it since I’ve been helping to organize the Forum for AI. Older speakers, who learned to speak before the advent of PowerPoint, seem far more likely to do as Greenspun suggests and use slides only for graphics. In Michael Ryan’s talk for example, his slides were mostly photographs of frogs, and graphical descriptions of the mathematics of his models. He may have had a few slides with bullet points covering important conclusions near the end, but for much of the talk he went for long stretches without changing his slides or refering to them at all. Instead he just talked to us, and he was quite engaging. The venerable Dr. Gerhard Werner, just put a slide with a picture of an ant in the document camera, and then spoke for an hour.
Since starting graduate school, I have not given a talk without using slides of some sort, slides almost always prepared using PowerPoint. I tend to think in outlines. I write all my papers by outlining and filling in, and PowerPoint makes that easy. It especially easy if you use their crappy premade talk templates, which I abhor. But even if you design your slides from scratch, PowerPoint makes it easy to be lazy and just write a bunch of slides that contain what are essentially notes for the speaker, better suited for 3×5 cards. I myself have been guilty of this at times, though I try hard to avoid it.
Still, you can’t lay the blame for speakers’ laziness on entirely PowerPoint. If there was no such thing, speakers would find other ways to be lazy, like writing out their entire talk and reading it to you. I think the thing to remember is that crafting a good talk is something that has to be learned, just like everything else. Except for a few people who are naturals, people who aren’t taught and don’t learn are going to give bad talks, regardless of what tools they use to prepare them.
In many cases, it comes down to each speakers’ personal style. If I’m just standing and speaking, I tend to get nervous and forget what to say. If I have something to interact with (and maybe some notes), the problem goes away. I think I actually do best at a chalkboard, where I can talk with my hands, but that’s not always possible, so I try to make slides with graphics or formulas that I can point to, and that complement and reinforce my spoken words. Sometimes, though, there are long stretches of speaking with no graphics, and I do resort to outlines with bullets, though I try to keep them sparse and avoid more than two levels of hierarchy. Even when in the audience, I find a well-crafted set of bullet-slides helpful, not horrific. They allow me to follow some train of thought started by something the speaker said, possibly missing his next few sentences, and then catch up by reading the slides. It’s also nice to be able to read ahead, get a preview of main ideas, and then have them repeated and elaborated by the speaker.
The key, of course, is that the speaker needs to spend time and effort crafting his talk and slides, and that the slides cannot hope to stand totally alone, without interaction and elaboration from the speaker.