A good example of this advice that spurred me to jot this post down is given at Presentation Advisors in the post Reducing the Amount of Text on your PowerPoint Slides. There’s much good advice in this post; e.g., “Filling slides with useless text can be detrimental to your presentation’s health… since the audience can’t read and listen at the same time, they’ll sometimes do neither”.

The important and valuable advice here (that’s also well-grounded in lots of research) is that you don’t want the listener to be trying to read and listen to text at the same time. So keep the amount of printed text low; most of the content and detail should be in what the speaker says. Excellent advice, I think.

But agreeing to that doesn’t entail adopting slides with the minimal amout of text on them. The valuable point is that the amount of reading should be minimal compared to the amount of listening. So my 55 minutes of 100-words-per-minute talking (5500 words if you’re keeping score at home) should be accompanied by a pretty small number of written words. Suppose I follow this plan and get my number of printed words down to, say, 200.

Great. But that doesn’t resolve whether those 200 words should be (more or less) 50 four-word slides, or 4 fifty-word slides. We’ve agreed to keep text down to about 4 printed words per minute. The question now is about how those words should be shown. And to answer that, the question has to be asked: What’s the point of having words up there at all?

Images and drawings have their place, and for people who are selling rather than teaching, or teaching certain kinds of material, pictures may matter a lot. But for those of us who are teaching, and especially teaching abstractly described rather than concretely pictured points (like me, a philosophy teacher), you’re going to want words — key concepts and terminology, important questions, conclusions, and steps along the way.

In short, you often want the words up there to summarize where you are in the medium-to-big picture; to remind them of their current place in the macro-level structure of the discussion; to keep telling them that the ephemera of what you happen to be saying right that second is significant because of the place it holds in the larger-scale discussion of the topic being considered. When it comes to words on the overhead, it’s all about summarizing and locating where you are.

So why not just a handout? Handouts have their place as well, and sometimes a handout is better. But often a lecture tells a story and takes you from one place to another; with a handout, the later chapters of the story are in front of them already, which may well undermine your ability to tell the story in the best way possible. I want the students to feel the force of an argument for a view, or an objection to that argument; a handout allows them to see exactly where we’re going, and relax about whether the current twist of logic might be the last word or not.

None of this means the more Lessig-ish style can’t work for some things, or that we should backslide into long discursive slides that have students tuning out just to read the text in front of them. But it does mean we should be careful about a potentially illegitimate inference from the reasonable advice of “minimize the ratio of projected words to spoken words” to the conclusion “minimize the number of words per overhead”. There are a variety of styles that embrace the good “minimize audience reading” advice; and not all of them minimize the amount of text per slide.

Update: There’s some thoughtful comments and discussion on this issue and this post over at Presentation Advisors‘ original post.

• 5. Salsa has always outsold ketchup.
• 6. Earvin “Magic” Johnson has always been HIV-positive.
• 9. Rap music has always been mainstream.
• 15. Babies have always had a Social Security Number.
• 22. The European Union has always existed.
• 30. There has always been a Cartoon Network.
• 32. Their folks could always reach for a Zoloft.
• 34. Women have always outnumbered men in college.
• 38. Belarus, Moldova, Ukraine, Uzbekistan, Armenia, Latvia, Georgia, Lithuania, and Estonia have always been independent nations.
• 68. Official racial classifications in South Africa have always been outlawed.

Students: Do not use “grandma/grandpa died” as your made-up excuse. Not only is it unseemly, but it is the paradigmatic false excuse, and we all know it.