Evidence-based presentation design
It's ironic: practicing Evidence-Based Management often involves presenting evidence, and yet the way we present that evidence frequently itself violates other evidence, evidence about effective presentation design.
Beliefs that only 7% of your message is in what you say and the rest is non-verbal, for example, or that each slide should contain seven bullets of seven words each, are based either on a faulty misreading of the empirical research or are directly contradicted by the research.
Fortunately, there is ample evidence—from research in communications, psychology, marketing, education, multimedia computing, and law—that can be used to establish design guidelines for effective presentations. The overall conclusion of this research is appealing from an EBM perspective: spend less time on decorating your slides and more time on perfecting your content—your evidence. Here are ten principles for evidence-based presentation design: the first three are about eliminating embellishment, and the following seven are about perfecting content.
Less time embellishing your slides
One of the most harmful consequences of the use of presentation software has been the ease with which such products enable users to add adornment to their presentations. Here the research indicates that, almost without exception, this not only wastes time but also hinders effective communication.
- Eliminate all irrelevant information or images
Several studies have shown that irrelevant images and details reduce audience comprehension and recall—in advertising, for example, irrelevant information weakens consumers' beliefs about product effectiveness. Even simple (but still irrelevant) elements as 3D effects in graphs can harm communication effectiveness. In general, anything that is not squarely focused on delivering or supporting your message seems to detract from it.
- Avoid slide transitions
Research indicates that using slide transitions reduces audience attention and agreement. Therefore avoid using fades, wipes, or “cha-ching” sounds when moving from one slide to the next.
- Use animation only if absolutely necessary
The only time that animation within a slide is useful is when the animation itself provides information that static images could not, such as when you are trying to explain how various complex parts of a process come together. Animation for its own sake is harmful to communication.
More time perfecting your content
To strengthen the effectiveness of your presentation, use the time you saved from not embellishing your slides to refine your argument, details, story, and graphics.
- Support your recommendations from multiple angles
The evidence here indicates that the more arguments and support you offer in favor of your recommendations, the more likely your audience will be persuaded. Perhaps surprisingly, you should also include arguments against your recommendations: this increases your credibility and protects you from counter-arguments. Lawyers call it “stealing thunder”: bringing up—and responding to—negative arguments before anyone else does significantly weakens those arguments.
- Provide details
Concrete details make your communication more interesting, memorable, and persuasive. The evidence here is that even the more conceptually oriented members of your audience, who may choose to ignore your details, will nevertheless perceive you to be more credible because you provided details.
- Explain why your recommendations will work
Experiments show that causal arguments (e.g. “adding this new feature increases customer satisfaction because it provides a sense of control”) are more persuasive than statistical evidence (“adding this feature increases customer satisfaction by 8%”).
- Weave your content into the form of a story
Stories are easier to remember than lists of evidence, in part because they allow the mind to make more connections, which improves memory. They are also more memorable to the extent that they engage emotions. Under some circumstances, people appear to take information that comes to them in a non-story form and turn it into a story. For example, legal research suggests that juries in criminal trials use a story approach to make sense of the trial data, and there is reason to believe that other audiences do this also. If your audience is going to turn your data into a story, why not help them by doing it for them? This way you will have more control over the story and make your presentation more memorable at the same time.
- Use graphics extensively
When graphics are included in presentation visuals (such as charts, diagrams, or photographs), then audience recall, persuasion, and positive attitudes to the material all improve.
- Keep material together
The evidence here is that—contrary to popular belief—breaking complex information down and presenting it in multiple simple pieces is actually less effective than presenting everything at once. This is likely because remembering each piece as it goes by is burdensome. Better to show the entire thing in all its complexity, and explain it. Other research concludes that presenting graphics and accompanying text close together in both space and time improves audience learning. So show a graphical representation of your complex information, place text labels right next to the more important parts of the graphic (this increases memorability), and explain the graphic verbally. For a sufficiently complex diagram, provide printed copies rather than projected slides because this allows you to use much finer detail and smaller type fonts, and therefore keep more of your information together on the same page.
- Use color for emphasis—and only for emphasis
Other than in color photographs—where the color used is natural—it would seem that the only role for color in serious communication is for emphasis. Research on print advertising found that where color is used to highlight or reinforce particular graphical elements, this tends to improve persuasion. But where color is used just for decoration, then the more likely outcome is that the audience will waste mental effort trying to decode the meaning of each color (“Why is that bar green and the other one blue…? Are they related to the green and blue frame around that text box…?) Black and white slides do not have this problem.
When you present evidence, make sure that you use presentation techniques that are themselves supported by evidence.