“No more than six words on a slide. EVER.”
That’s the advice of Seth Godin in “Really BAD PowerPoint (and how to avoid it).”
Here’s his rationale: “Communication is the transfer of emotion.” Too many words on the slide prevent you from connecting emotionally with your audience. Moreover, a PowerPoint slide shouldn’t serve as the script for your presentation.
Still, I think Godin is too tough on PowerPoint. I like the rule about using at least 30-point type on your slides. It puts a useful upper limit on the number of words you cram onto one slide. I first saw this rule in Guy Kawasaki’s “The 10/20/30 Rule of PowerPoint.”