Presentation professor Andrew Abela says, while ball room style presentations are all about keeping control over the presentation and over the audience, board room style presentations are about sharing control. Handing out copies of your slides allows people to proceed at their own pace and take notes on the slides if they want. It also allows you the presenter to easily see who is having problems keeping up (they keep looking over the previous slides) or who thinks the presentation is going too slow (they keep reading ahead to the upcoming slides).
Out of control,
Tim Wilson
Professional Speech Coach
Free speaking tips at: http://speakingquicktips.blogspot.com
