Researchers at UNSW recently released findings indicating that the conventional use of PowerPoint is extremely ineffective. Specifically, they point the finger at the habit of reading what is written on the screen. This is counterproductive, they claim, because the brain is ineffective at simultaneously processing written and spoken information. Thus, when a viewer is following along with the presenter, reading what is written on the screen, their retention is significantly less than if the information were presented either just in written or just in spoken format.
This is music to my ears and confirms a belief that I have long held. Screen presentations should be used to present complementary information to what the presenter say, not repeat the same information. Whenever I attend a talk where the presenter has carefully written out bullet points and essentially reads what is written on the screen, I cringe and think what an amateur presenter they are. As a rule of thumb I advocate the following guidelines when writing screen presentations. First, never write entire sentences or, even worse, paragraphs. Keep text to an absolute minimum and when used make it as simple and concise as possible. Second, favour graphics over text. This is a good way to avoid repeating what you say in written form. Third, never read from the screen or repeat exactly what is written on the screen. Finally, never use those ridiculous screen transitions. They're cute, but they only distract the audience from what it is you're trying to convey.