Imagine that you are driving while listening to the radio and talking to a passenger sitting next to you. You are processing multiple sensory channels simultaneously. You are watching (the road), listening (to the radio and your friend), and thinking and talking. This doesn’t sound too difficult. People process multiple sensory channels all the time. But there is a limit. If one of the channels becomes complicated or difficult to process, then processing more than one channel can get very challenging. For example, what if there is a sudden storm while you are driving, and torrential rain makes it hard to see the road? It will start to get hard to pay attention to, or remember, what your friend is saying.
The visual channel trumps all others — Of all of our senses vision takes up the most area of our brains. Humans are very visual animals. So if there is something to listen to, or something to look at, looking will get first priority (an exception would be a large startling noise).
Listening and reading don’t mix well — During a presentation, there are two sensory channels that are most active: visual and auditory. Your audience might be looking at you while also looking at your slides. They are also listening to what you’re saying. If the slides are visuals that are easy to understand—such as photos, or diagrams that add extra context and meaning to the presentation—then the multiple channels are a positive experience for them. But if, instead, the slides are hard to read or complicated, then they will be distracted. In particular, the sensory combination of slides that are filled with text and a speaker who is talking is a bad combination. In order to understand the slides, your audience has to read. As soon as they are reading, they are not listening. Listening and reading are two sensory channels that compete with each other.
What to do instead of using wordy slides — You don’t have to use slides in a presentation:
- Put your presentation together without slides first, then decide if any of your points would be enhanced by the use of a visual example or illustration.
- If you use slides, use them for simple photos, diagrams, or illustrations.
- Don’t put more than a few words of text on a slide. If people are reading, then they aren’t listening to you.
- Know what to call slides with a lot of text on them? Your notes! If you feel you need slides with text, it’s probably because you need notes. Don’t show the audience your notes.
For more suggestions about how to be a great presenter, go to the rest of the posts in this series, and check out my latest book in the sidebar on the right: 100 Things Every Presenter Needs To Know About People