Research by Professor John Sweller of the University of New South Wales suggests that when people see PowerPoint presentations that simply repeat what the presenter is saying, the brain responds to this ‘cognitive load’ by shutting down.
“It is effective to speak to a diagram, because it presents information in a different form.” says Sweller. “But it is not effective to speak the same words that are written, because it is putting too much load on the mind and decreases your ability to understand what is being presented.”
Now I hate clip art almost as much as I hate the use of exclamation marks in badly written copy. But I will be using well chosen, quality imagery instead of bullet points in my next presentation.