Your slide design has the power to increase or decrease how much of your talk your audience actually hears. Hard to believe? Let's dig in.

If you haven't already read it, be sure to check out Designing Engaging Presentations Part 1.

Mental Gymnastics

Imagine trying to listen to two people tell you the same thing: one person is speaking very fast and the other is speaking at a normal pace. Most likely, your mind would bounce from speaker to speaker; you may retain some information, but it would be significantly less than if one person were speaking to you at a normal pace.

If you present your audience with a slide full of text, they will be almost irresistibly drawn to read that text. If you are also talking to them (whether it’s the same verbal content or not), it will produce the dual-voice scenario above.

It's not surprising, then, that we might have a hard time reading and listening to someone speak at the same time. A 2015 Georgetown University study demonstrated that our brains are processing word shapes using the part of our brain we use to recognize faces. Once our brain has identified the word by shape, a study at the University of Pavia in Italy found that it then reads the text aloud to us internally, where we process it with the same part of the brain we use to process spoken words. If you add someone speaking simultaneously, you'll be listening to two conversations at once and there's little chance you'll leave with all (or much) of the information.

Furthermore, your audience can read your slide much faster than you can talk, so if your verbal presentation is mostly reading or rephrasing the words on the slide, they will have already read ahead before you’re a few sentences into your slide, and will lose interest in your presentation very quickly.

Towards Simplicity

So how can you translate this knowledge into your presentations? First and foremost, embrace simplicity in your slides. When possible, use a one-idea-per-slide format and make that idea as visual as possible. Leverage memorable images or videos that are relevant to your content, and when you must use text, use it sparingly with visual signaling to indicate where the audience should be focused as you are speaking. Let's compare two approaches to introducing the topic of visual signaling. First, the traditional bulleted approach:

Contrast that with this brief presentation with voice-over explaining and demonstrating Mayer's Signaling Principle:

It’s clear that a narrative supported by images and video with minimal text provides the most engaging and memorable experience for your audience. Save the text-only outlines for a post-presentation handout. Design your slides to minimize distractions and help your audience connect with your story. Where possible, every idea should have its own slide, and every slide should be as simple as possible. Trust me, your audience will thank you for it.

Cover photo source.