This is your BRAIN on Powerpoint - part 2-01

This is your Brain on PowerPoint part #2

Yesterday we looked at a recent paper from the Stanford psychologist Stephen Kosslyn and a team of researchers that outlines eight psychological principles that every presenter should follow to create effective slides. We explained the first four principles: The Principle of Discriminability, The Principle of Perceptual Organization, The Principle of Salience States and The Principle of Limited Capacity. Or – Make it stand out. Intentionally cluster and organize. Make it a big difference, only if there is a big difference. You know too much and they don’t care.

Today we are going to pick up where we left off by and look at the next four principles. Tomorrow, we’ll unveil the top three most violated principles.

5) The Principle of Informative Change -or- With New Information, Change

Research shows that if you change something, (a word or a graphic) your audience will expect new information. This means that when your PowerPoint includes a perceptible change make sure it’s worth it. A change implies a new piece of information is coming. If you don’t deliver on that subconscious promise, you will add to the confusion. Section Headers and Closers are usually the first to go when a presentation is judged too long. (and don’t get me started on why a slide count is the measure of both length, quality and substance of a presentation) so as you move through your presentation make sure you clearly mark the beginnings and endings of each section. As the researchers say, “the very concept of ‘information’ has been defined in terms of change: only when there is a change is information conveyed.”

Lesson: Use markers to show organization and progress through your presentation. Don’t throw away the section headers.


6) The Principle of Appropriate Knowledge -or- Don’t Try to Sound too Smart

It’s easy to forget that your audience doesn’t know every single thing you know. It’s also easy to assume that your audience will “get” everything you explain the moment you explain it. Of course, most of the time presenters are leapfrogging and hopscotching their ideas so quickly that the audience quietly slips into dreamland. The principle of appropriate knowledge is a reminder of the obvious: “Communication requires prior knowledge of relevant concepts, jargon, and symbols.” This means that if you rely on “novel concepts, jargon, or symbols, the audience members will fail to understand.”

Lesson: Speak to an eight-year old. Don’t rely on buzzwords, corporate pig-latin, novel concepts, or jargon monoxide.


7) The Principle of Compatibility -or- Be Visually Consistent

If you don’t know the name “Stroop Effect” you’ve definitely seen it. It’s the one where you have to name the color of the ink used to spell words of colors that are different from the ink – for example, red ink used to spell blue. It’s not easy. This is because your brain is trying to sort out the meaning of the word from its perceptual properties. In psych-speak, “The meaning of a stimulus will be difficult to extract if the interpretation of its surface properties (such as the size or color) is inconsistent with its symbolic meaning.” So when it comes to your PowerPoint using an old-fashioned typeface to describe a high-tech device is a no-no. A chart showing growth outlined in red is a bad idea.

Lesson: Make sure the visuals show what you’re talking about.


8) The Principle of Relevance -or- The Goldilocks Principle

One spoonful of cough medicine will probably help that tickly cough, but it’s probably unwise to drink the whole bottle. Yes, the purpose of your PowerPoint presentation is to convey information, but that doesn’t mean you should convey as much information as possible. With too much information you’re asking your audience to search for the relevant stuff. That’s mentally tiring. With too little, they are left searching for answers. According to Kosslyn et al, “communication is most effective when neither too much nor too little information is presented.” They didn’t mention Goldilocks or any porridge bowls, but they should have.

Lesson: Not too much and not too little. Go for just right. Also, not too novel but don’t dumb down.


Further Reading:

Read the Kossyln Study: PowerPoint® presentation flaws and failures: a psychological analysis.
Stephen M. Kosslyn1*, Rogier A. Kievit2, Alexandra G. Russell, 3 and Jennifer M. Shephard4

  1. Center for Advanced Study in the Behavioral Sciences, Stanford University, Stanford, CA USA
  2. Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
  3. Department of Psychology, Stanford University, Stanford, CA, USA
  4. Division of Social Science, Harvard University, Cambridge, MA, USA

Gavin_Animated-GifGavin is a founding partner at fassforward consulting group. He blogs about PowerPoint, Presenting, Communication and Message Discipline at You can follow him on twitter @powerfulpoint.

More at Google+Facebook and Pinterest. Comments are welcome, links are appreciated. If you’re interested in writing guest posts for this blog, please contact me.


  1. systimplicity | September 26, 2012 at 8:21 am

    Principle #6 – No jargonic BS! I’m gaining a lot from your blog posts. My PowerPoint presentation requires a rework each time I read another post! Two weeks before I present so wondering how many more blog posts between now and then and therefore how many more reworks:) Thanks, I appreciate your work.

  2. Pingback: 8 Powerful Points for an Awesome PowerPoint | Daydreamer Overload

Leave a Reply