I was talking this week to a very nice group of folks who were prepping me for a speech to their organization in December. We first talked about the audience, their issues, what they needed to hear, and what was keeping them up at night. Then, we discussed logistics.

And during the course of this logistics discussion, The Question came up, as it always does: are you going to use slides?

Now, the truth is that I hate slides, as readers of this blog will know. I don’t think a good speaker needs them, and I don’t think they aid in comprehension for the audience, either. I have a lot of research on multitasking to back up those opinions.

I do have huge respect for people like Seth Godin and David Meerman Scott who run through a glitzy slide deck while they speak and use the deck as a counterpoint commentary on that talk. They make it work. Seth makes it work because he uses the slides as punch lines for his jokes and insights. David makes it work because he’s talking about the latest companies and digital ideas in marketing and real time business, and he illustrates his points with web page grabs, videos, and the like.

Fair enough. But for most of us, who have a body of knowledge to talk about and some stories to tell, slideware is supererogatory.

A misconception that I frequently hear as a speech coach is the idea that slideware helps because all people are one of the following: visual, kinesthetic, or aural learners. Neither idea buried in this generally accepted, appalling misconception is true.

First of all, we’re all visual learners. We can handle up to 10 million visual bits of information per second, far more than anything else our minds can process. We’re also all kinesthetic and aural learners. We get information in those other ways, too. Just not as much. Of course, there are individual variations, but most of us are average, and that means we’re mostly visual beings. Unlike, say, cats and dogs, which have vastly more developed senses of smell. For us, it’s visual.

Second, slideware doesn’t help; it distracts. All the research on multitasking shows that we can’t do it. We first pay attention to one thing, and then another. Moreover, the research on how our brains process visual information indicates that we don’t actually see what’s in front of us, but rather an approximation of it that our brain matches to reality based on its memory banks.

So what really happens when we’re confronted in a meeting or a presentation with a speaker and a set of slides is that we look at the speaker—because we’re inherently more interested in people than pictures—and when our attentions start to wander, then we look at the slides. Now, reading slides and looking at people occupy two different parts of our brain, and there’s a lot of inefficiency in switching back and forth. So when we’re looking at the speaker, we’re getting one set of cues. When we look at the slides, we get another set. When we switch, we lose a bit of either information stream.

The result is two incomplete sets of information. That’s tiring and indeed annoying for us, so we get cranky and tune out.

That’s what slideware does. With some exceptions, it adds to our information load, overwhelming it even faster, and causing us to tune out.

Don’t do it.

Now, I need to work up the chutzpah to tell those nice folks that I won’t use slides.