This is your Brain on PowerPoint part #3

In two previous posts, we covered the eight principles of human perception, memory, and comprehension cited by Kossyln and his team in their experiments on PowerPoint. They conducted three experiments for their study, involving several hundred participants and a team of judges who evaluated PowerPoint slides. After “[analyzing] how well PowerPoint® slideshows, slides, and presentations respect principles of human perception, memory, and comprehension” they found that the three most-violated principles were:

(drum roll, please…)

1) Discriminability (because material that made different points was too similar to be easily distinguished)


2) Limited Capacity (because too much information was stuffed onto a slide),


3) Informative Change (because random changes in how information was presented didn’t reflect an actual change).


Cast an eye over your latest slide deck. Are you making these mistakes? Are you clearly making a point on each slide and have you made that point stick out (Discriminability). Have you stuffed too much information on a slide and maybe you’re finding it difficult to edit down? Have you been inconsistent for no reason? Perhaps on one slide you introduced a group of concepts in a column, and on the next slide because of space constraints, you stuck them in a row?

According to the research, all eight principles are broken on a regular basis. Scientific proof that your PowerPoint slides probably aren’t that great. Here are the scientists concluding remarks:

In the three studies reported here, we analyzed how well PowerPoint® slideshows, slides, and presentations respect principles of human perception, memory, and comprehension. Specifically, we hypothesized and found that the psychological principles are often violated in PowerPoint® slideshows across different fields (Study 1), that some types of presentation flaws are noticeable and annoying to audience members (Study 2), and that observers have difficulty identifying many violations in graphical displays in individual slides (Study 3).

So the next time to sit down to create PowerPoint slides remember 9 out of 10 scientists agree, you’re doing it wrong.* Use the principles. They might keep your audience from zoning out.

*this statement is a complete fabrication. It’s one study. But it was done by real scientists. You can read it below.

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 makeapowerfulpoint.com. You can follow him on twitter @powerfulpoint.

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  1. Peter | September 29, 2012 at 11:46 am

    Wishing I could make the reading of this post compulsory for everybody who works in the tech sector

    • Gavin | September 29, 2012 at 2:30 pm

      Peter, now you have a pseudo-scientific reason to say, “I think that’s cr#p… and here’s why…”

  2. Richard I. Garber | September 30, 2012 at 11:31 am


    Three excellent posts in a row!

    At the beginning of September I made a another series of blog posts summarizing those three studies presented in the Kosslyn et al article:

    Power Point Flaws and Failures: Rules Commonly Broken:

    PowerPoint Flaws and Failures: Survey of Common Flaws and Annoyances:

    PowerPoint Flaws and Failures: Do People Know and Understand What They’re Doing:


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