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A psychological analysis of problems in powerpoint presentations.

A God-awful powerpoint slide I found on the web. Don’t do this. Ever.

Powerpoint (or I guess Keynote, if you’re super-cool) presentations – love ’em or loathe ’em, they have become an integral part of the academic and business world. I can’t really imagine doing a lecture or talk without using powerpoint in at least some small way these days. However there’s nothing worse than a bad powerpoint presentation – we’ve all seen them. The colours are garish and clashing, the text is illegible, the organisation is incoherent, and the illustrations are irrelevant or actively misleading. How can we avoid these mistakes in our own presentations, and ensure that we craft a well-structured, pleasant-looking presentation which will add to the impact of what we say, rather than detract from it?

A quick Google of ‘how to make a great powerpoint‘ brings up 144 million pages (including, interestingly, one from Microsoft itself), many of which contain conflicting information (I assume they do anyway, I haven’t read them all). Fear not though, gentle reader; the inimitable Stephen Kosslyn (and colleagues) of Stanford University has just published a paper with the intriguing title of “PowerPoint® presentation flaws and failures: a psychological analysis” in which the common flaws in presentations are deconstructed with an eye to the psychological principles of effective communication. This is great, because it not only points out what’s often wrong with slides, it give some clue as to why these things are wrong. You can read the paper here (free HTML full text – yay!) or download a PDF from the link on the top right.

Kosslyn et al.’s analysis is based on “Eight cognitive communication principles”:

  • Discriminability
  • Perceptual organisation
  • Salience
  • Limited capacity (of working memory)
  • Informative change
  • Appropriate knowledge
  • Compatibility
  • Relevance

…and it’s proposed that optimising presentations in terms of these cognitive principles will produce greater engagement, understanding and retention of the material, by the audience. The authors then followed up this fairly abstract classification with a series of three studies; rating real-world slideshows from various domains (academic, business, governmental) on sub-units of these eight features, showing that flaws are noticeable and annoying to the audience, but also that people often have difficulty identifying the exact flaw in a given slide.

The results suggest that adherence to good practice when designing slides is important, but that a lot of people’s intuitions about what makes a good powerpoint are themselves flawed. Some people may have an ‘eye’ for good, clean design, whereas others might not be able to avoid making some obvious mistakes. I won’t repeat any more of the papers results here, but I urge anyone who relies on powerpoint to go and read the paper and assimilate its findings into their next presentation.


PS. Another excellent write-up of this paper is here.


How to Program Experiments 1: Cheating with Powerpoint

And here we finally are; it’s something I’ve been avoiding getting around to for a while, because it’s such a big and complicated topic, but to a large extent it’s the raison d’etre behind this entire blog, so I knew I’d have to roll up my sleeves and get down to it eventually. The topic I’m referring to is of course, how do you make a computer perform those nice cognitive-type psychology experiments? How do you get it to put pictures, words, or videos up on the screen, collect responses, store the data and do it all with accurate timing? How, in a nutshell, do you make a computer your all-singin’, all-dancin’, research-data-collectin’ bitch?

As I said, this is a massive topic, so before getting into specialised software and ‘proper’ experimental programming we’re going to start slowly, and we’re going to start with some techniques for using a piece of software that’s on practically every PC – Microsoft Powerpoint. Powerpoint is essentially just a program for presenting multimedia (words, pictures, video, sounds) on a screen in a nice professional way, so we can use it for presenting some simple experimental stimuli. The one thing that it won’t really do is collect input from a participant (except the standard ‘advance to the next slide’ input), which is a pretty big limitation for experimental purposes, but can be worked around.

The best ways of explaining how to use Powerpoint are by example, so I’ve created a couple of illustrative slideshows.

The first one is a simple rating task, where pictures of faces are presented, and a Visual Analogue Scale (VAS) is presented on-screen underneath each picture, like this:

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