Even though we just discussed the fact that there are six major purposes, one stands out among the rest: to persuade.
Take the salesman at a large Canadian telephone company who recently told me about a presentation he was going to give. He'd been asked to observe a new telemarketers' training program for three months, then present an evaluation to company executives. When I asked him what the purpose of his presentation was, he said it was to inform the company executives on the status of the program. But as we spoke, he came to realize that he really wanted the executives to sign up for a long-term commitment to the program. His real purpose was to activate, not just inform. When his purpose changed, so did his entire presentation.
The speaker's task is seldom as simple as imparting information. Granted, informing is central to the job; speaking is an efficient way of conveying timely information to large groups. But chances are your objectives as a speaker are to persuade, to give your audience new information in such a way that it sees things your way. This is the purpose behind the purpose, the end result that speakers seek.
You can see these two goals—informing and persuading—at work in business and technical presentations, where the topics, the facts, and the statistics are presented with a clear objective in sight: to win that account, reorganize that department, or revamp that computer system. As tools of persuasion, speeches and presentations are everyday events. But it's not enough to be clear; you need to be compelling too.
I once heard a principal speak to the parents of his students about drunk driving, a subject of such inherent seriousness that he should have been able to lead the parents with ease. But he never made his purpose clear: His facts and presentation were jumbled; his stories weren't focused; and up until the very end, the parents were left wondering what the point was.
In fact, he had a very specific point. He wanted the audience to write letters to the legislature supporting tougher laws. But because he waited until the last few sentences to spring this request on them—instead of weaving the effect concerned citizens can have throughout his talk—his audience felt more put upon than activated.
He made the mistake of thinking that informing is the same as persuading. It's not. Informing is a preliminary step to getting people to act, but facts need support, organization, and clear communication of benefits to get results from an audience.