Multimedia Dissonance

Professional collaboration last Friday.

I sat through three or four PowerPoint sessions, several hours to ponder a) under what circumstances should one person address a large, captive, immobile, and mostly mute audience and b) how to do it well, if one is so called.

Half a legal pad later and I’ve got kind of a detailed post to share with you all this week (one which probably deserves some criticism). Before I drop it, though, I’ve gotta set up this one concept which I’ve termed “multimedia dissonance,” a name which feels appropriate only ’cause I haven’t seen it explicitly defined elsewhere.

Multimedia Dissonance Cognitive Overload

It’s what happens when you’re in front of an audience reading (or reciting) any amount of text that exists in the same presentation in another medium.

For Example

Like when you’re reading the same text that PowerPoint’s projecting over your shoulder.

This isn’t about aesthetics or bullet points. It doesn’t matter if the text is laid out nicely and poorly. This is about information trying to find an avenue towards your audience’s collective brain while multimedia dissonance overturns cars and sets bridges on fire along the way.

It’s like this:

Text-Only Is Good

Audio-Only Is Good


Both Together Is Multimedia Dissonance

Go ahead and play the audio while reading the slide. If you’re like me, like the cases John Sweller researched, you immediately notice the dissonance between the two, the slight instances where audio and text diverge. The added “finally” where none exists in the text. The extra “… and in a big way ….”

It’s a lot like that old psychological chestnut. Read the following line aloud:

red green blue green red blue

And then read this line aloud:

red green blue green red blue

That’s dissonance. It won’t sink a presentation. I reckon you lagged by only fractions of a second on that second line.

But compound those fractions of seconds across sixty slides across everyone in your audience and all of the sudden you’re the reason why people get this dry taste in their mouths when they hear the word “PowerPoint.”

The Best Alternative

As I revamp last year’s math slides, I find myself unexceptionally deleting text, building conversations around visuals rather than building conversations into them.

Play the audio while looking at this visual and you’ve got “multimedia assonance” (I’ll spare you the definition).

The sum of the two is greater than its parts.

There’s more I’d like to say about this.


  1. The Uncanny Valley:

    The name captures the idea that a robot which is “almost human” will seem overly “strange” to a human being and thus will fail to evoke the empathetic response required for productive human-robot interaction.

[Update: Chris Craft says I’m staking out territory that’s long been claimed. The term is “cognitive overload,” and it means it’s time for me to renew my library card and grab some books.]

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.


  1. Time for a theoretical basis for what you’re espousing. You’re beginning to hit the basics of Cognitive Load Theory, which is researched and quite extensively written about. Sweller is considered the originator, and you ought to read up on it. It will give you some vocabulary.

    For example, the multimedia dissonance you talk about is really just cognitive overload. Folks reading the slides is ineffective because the audience can read them faster than the speaker can speak them. When you are reading at the same time, you hit cognitive overload. The theory also lends itself nicely to removing a lot of the extraneous load in a presentation, such as the silly little transitions that are pointless and the sound effects (clapping, racecar, etc).

    This is an entire course we’re talking about, and I’ve given you the basics. Read up on it, it fits nicely as to where you’re going with this.

    Chris Craft

  2. There is also a piece of research which I can’t put my hands on at the moment which states that retention of ideas is less when you read the text. Perhaps that’s the cognitive load theory in action but regardless, I’d like to find that data again to nail down the facts and rid the world once and for all of lousy slides.

  3. Dan,

    Actually, the technical term you are writing about is properly referred to as:

    “Staffis Prepus Auralrectalopticalism”.

    Loosely translated is means:

    “the poor use of audio visual input gives people a shitty outlook on staff training”.


  4. Ah, right up my presentation, good man.

    Yes, this is all been-there-done-that sort of territory. Last year, I eliminated text from all PowerPoint presentations. The results were stunning:

    1. 17 of 18 students actually seemed to know their content b/c they were no longer reading bullet points.
    2. They recognized that the presentation wasn’t for them, but for the audience.
    3. Student #18 took a zero, citing “there’s no way I can do this without my notes up there.”

    Forgive me for no hyper-linking here, but I’m tired of direct entry HTML:

    – check out – clear, thorough, and just gosh-darn useful.

    – Jeff Utecht just made one of his own Pecha Kucha (or, ‘Get to your point in 20 slides and then sit the hell down’). Worth a lookee-listenee.

    If you’ve seen/heard one or both, well nothin’ wrong w/ some old-fashioned repetition.

    Me loves the presentations…and JarJar Binks.