PowerPoint Tip: “How Many Slides?” is the wrong question to ask
I often get asked in workshops, “How many slides should I have for an x minute presentation?” And I’ve now come to the conclusion that this isn’t even the right question to be asking. In the past, when we put up a slide and spoke to it, we counted the number of slides. Today, I think the relevant measure is how many different visual impressions are used.
By a visual impression, I mean something different on the screen for the audience to look at. For example, let’s say you have one slide and it has a headline and three images with text underneath each image. To explain each point individually, you build the slide so each image appears with the corresponding text. I suggest that you would then have four visual impressions: 1) the slide with just the headline, which introduces the topic you will be talking about, 2) the slide with the first image and text added, 3) the slide with the second image and text added, and 4) the slide with now all images and text appearing.
So if the right question to ask is “How many visual impressions should I have?”, then I think we can get guidance from the visual medium most people are familiar with – television. To get a sense of how many visual impressions TV uses, I looked at two brief news clips on CNN.com recently that are representative of typical TV clips. One was produced by CNN and profiled one of the people considered a CNN Hero for the charitable work they do. The other was a news story produced in the UK by ITV news. In TV, any new segment of the story is a new visual impression, but any new camera angle is also a new visual impression. In the CNN clip, they showed 33 visual impressions in 96 seconds and the ITV piece used 12 visual impressions in 86 seconds. So, on average, they are showing a new visual impression every 7 seconds or even sooner.
Why does television do this? Because it keeps our attention. And attention means we are listening to the story and taking in the message. This has significant implications for business presenters who want their audiences to pay attention to the message being delivered. It is no longer good enough to put up a slide and talk about it for two minutes. People aren’t going to pay attention for that long since they have been conditioned to see visual impressions more often than every few minutes.
Remember that people are not comparing your presentation to a presentation from a colleague. They are comparing your presentation to the other visual media they see. So you are competing with television whether you like it or not. Should you be having a new visual impression every 7 seconds? I don’t think you need to go that far, but here are two suggestions to consider that will increase the number of visual impressions that you use in your presentations without having to change the content.
First, build each point on your slides. If you have multiple bullet points, build each one so you can discuss each item individually and keep the audience’s attention with a new visual impression. If you are using a visual such as a diagram or graph, build the parts of the visual and the callout as you speak about that point. Each new part of the visual will be a new visual impression for the audience. Building points on your slide is the fifth step in my five-step KWICK method from my book The Visual Slide Revolution. In the book I state it as "K- Keep Focus" because building our points keeps the audience focused on what we want them to hear.
Second, remember that you are a visual impression as well. Turn off the slides once in a while and have the audience focus just on you when you deliver a powerful point that does not need visual support. Just by implementing these two suggestions, you will increase the number of visual impressions you use and better focus the audience on your message.
I think you can go even further by using persuasive PowerPoint visuals instead of text slides to increase the impact of your communication. When you are ready to take your presentations to that next level, check out my book The Visual Slide Revolution. You’ll learn how to create a visual to replace text and the steps are easy to apply to your own slides.