The term “slide” (as in PowerPoint) comes from the old, 35mm film slides. An alternative to getting your film developed as prints, They consisted entirely of the image itself turned into a transparency. No text. No bullets. No animations. Just visuals that could be projected while the speaker spoke. Often about his summer vacation.
In some ways it seems like we’d be better off if we went back to this format.
Humans are really good at understanding verbal and visual input, like full-screen images with a speaker speaking to them. So the old, 35mm presentations worked perfectly.
Humans are really pretty bad, though, at processing more than one stream of verbal input at a time. We really can’t read a slide and listen to the speaker at the same time. One of the signals has to get ignored.
PowerPoint, Keynote, Prezi, and all the other slide creation tools give us the ability to do so many amazing things with slides. But it’s important not to lose sight of how an audience learns effectively and make sure we take advantage of that.
Using full screen images and eliminating as much text as possible is what I’ve found to be the most effective.