But, malaria — even the million deaths a year caused by malaria greatly understate its impact. Over 200 million people at any one time are suffering from it. It means that you can’t get the economies in these areas going because it just holds things back so much. Now, malaria is of course transmitted by mosquitoes. I brought some here, just so you could experience this. We’ll let those roam around the auditorium a little bit. (Laughter) There’s no reason only poor people should have the experience. (Laughter) (Applause) Those mosquitoes are not infected.TED saw a surge in Twitter activity around this talk and this tactic, which must have had more than a few audience members itching in their seats. And Gates isn't the only high-profile speaker to use a dynamic prop. Also among my favorites:
- Neuroeconomist Paul Zak sprayed the TED stage with oxytocin from a syringe while discussing the link between this hormone and feelings of trust and morality. Just a squirt, mind you; and
- At TEDMED, engineer and beat-boxer Nate Ball sat on stage while a laryngoscope was put down this throat to give the audience an up-close view of his vocal chords while he improvised a beat; an fMRI gave the audience a view of what the improvisation did to his brain at the same time.
- What's the desired effect on your listeners? Do you want to puzzle them--and keep the puzzle going till the end of your talk? Create the kind of uncomfortable suspense that worked in Gates's talk? Make an abstract concept like a hormone or an unseen thing like the back of your throat concrete? Think through the effect on your audience. I have to admit that seeing the laryngoscope go up Ball's nostril and into his throat made me shiver involuntarily at TEDMED; a physician next to me leaned over and said, "That doesn't hurt as much as it looks like it does." It's not a bad thing to make the audience uncomfortable if that's part of your plan and understanding.
- How recognizable is it? If you're wielding something that the audience doesn't recognize, you'll need to spend extra time in your presentation explaining it. Factor in extra time for the hard-to-discern prop, or consider whether you need it.
- Can you edit your use of the prop? By no means should you use more than one prop (unless you host a children's live-television show, that is). But even if you only have one, make sure it's not taking up all the time of your talk. That squirt of oxytocin took a moment, but conveyed a more palpable sense of the hormone, and the idea of spreading trust. Even the most elaborate prop in our examples--the laryngoscope--does not dominate the talk. Make sure you are not upstaged by your devices.
- Is it quick and easy to operate? Props require practice, in part to make sure they don't take up too much time. If your prop takes time and effort to operate, get a partner to help, or ditch the prop.
- What might go wrong? In Nate Ball's video, below, physician Charles Limb is enlisted to help with the demo. But as Limb describes, he discovered he wasn't licensed to perform a laryngoscopy in California, where TEDMED took place. Fortunately, a qualified physician from the state also was a speaker, and stepped in to help. Think through your own prop, its use and preparation, its travel needs and all the other things that can go wrong. How would you do the talk if it suddenly weren't available?
- What do setup and cleanup look like? If your prop explodes, breaks into pieces on purpose, sheds a liquid, or requires elaborate preparations to get it onstage, take the time to talk to the conference or talk organizer, audio-visual crew or stagehands well in advance. Can you get rehearsal time for a run-through with all hands on deck? Will you be distracted right before you begin speaking by an over-wrought setup?