Confusing an audience is always a mistake.
But being precise, definitive, and conclusive in a speech isn’t always a virtue.
Sometimes your goal as a speaker is to educate your audience. Or it’s to persuade them to take a specific action—to support your initiative, to green light your project, to implement your procedure.
In those cases—and in most workplace presentations—you’ll want to avoid any and all ambiguity. By the end of your speech, your audience should know exactly, in no uncertain terms, what your point is and what you want them to do.
But when you seek to inspire an audience, you need to take a more open-ended approach.
Sometimes, when you’ve finished speaking, you want the audience to have more questions than answers. More wonder, less certainty. More to think about, mull over, and investigate.
Sometimes you want to plant an idea in people’s imaginations and trust them to bring it to fruition.
Sometimes you want people to invest your words with their own wisdom. And you’re willing—wanting—to see where that takes them. Even if it’s in a direction you had never imagined.
Ambiguous can mean obscure, vague, or cryptic. Which isn’t what I’m advocating. It can also mean “open to more than one interpretation.” Which is a quality many great speeches share.
If everyone in your audiences ends up thinking exactly the same way, you may have given an effective speech. When they each have a different take on what you’ve said, a unique insight, you may—you may—have done them a better service.