Speaking: Explaining Technical Information to a Mixed Audience

It’s a challenge to present deeply technical material to a room of people with varying expertise levels. If you leave it out, you’re abandoning the substance of your presentation. If you focus on it exclusively, you will lose most of the room.

Instead, include the material, but plan to repeat it two (or even three!) times.

The first time you explain it, explain it for the expert audience.

The second time you explain it, walk through an example of what the system enables.

If you’re audience is on Twitter, throw in a third version — the concise and tweetable one!

Let’s say we were giving a talk about a machine learning system to classify puppies.

Slide one would have a technical diagram of the architecture of the system, and you might explain it as: “We use a naive bayesian classifier over two hundred features to discriminate between puppies and non-puppies in our data set. As you see, our system is 85% accurate and each analysis takes 300 milliseconds. We implemented the classifier in Python, using the scikits-learn toolkit…” Don’t skimp on the details, but don’t use more than one slide for this part if possible and the explanation shouldn’t take more than a few minutes.

Slide two would have images of puppies and non-puppies, and might be explained, “This means that we have an algorithm that can distinguish between the puppies you see on top and the other objects quite accurately and quickly using features like ear floppiness and nose size.”

Slide three would be the cutest puppy you can find, and you might say, “Yes, we’ve created the worlds fastest cuteness identifying machine!” Only include the third version if the audience is online anyway. They’re probably only paying half-attention to you as you speak and this gives them something concise to share and take away from your talk.

The technique of repeating the information at varying levels of intensity has the side effect of walking people through to understanding. They may still be puzzling through the technical material when you explain it non-technically, and this seems to help the meaning snap into focus.

Break up your technical material with layered explanations and you’ll keep the audience entertained while maximizing the amount of information that each person takes away. Win.


  • http://lkb.cc/ Leonard Bogdonoff

    You got me at ear floppiness.

  • quasiben

    How did you decide to structure slides technical->overview instead of overview->technical?

    • http://www.hilarymason.com Hilary Mason

      I always give a brief (few word) introduction to what I’m talking about before the technical details, but I’ve tried both ways and the technical details -> non-technical walkthrough seems to be the most successful.

      • http://twitter.com/luzeng Lu Zeng

        My guess for why this is true:

        If you go technical -> overview, the technical portion of the audience will be satisfied with hard facts right away, and the non-technical portion of the audience will feel like they’re getting it more and more (“walking people through to understanding”).

        The other way around, the non-technical audience will get the “oh, now you’ve lost me” feeling, and the technical audience will be tapping their collective foot for the details.

  • http://www.facebook.com/DJhiQ Chris Larsen

    Windeed :)

  • Emilio López

    Pretty interesting approach! in my education we have to defend our final thesis and many relatives of the speaker will show up to the final presentation. I always see very confused and scared faces every time an event like this takes place, I will definitely keep this information in mind!

    EMILIO!

    • http://www.hilarymason.com Hilary Mason

      Cool! But don’t forget that the primary purpose of a thesis defense is to please your committee. :)

  • Wei

    Paul brought me here, good one buddy :)

  • James D

    This is really helpful. Would you use the same technical->overview format in a static document, like a slide deck?

  • Jayron Ageu Soares

    nice blog! cheers from Brazil :D

  • http://twitter.com/JakCharlton Jak Charlton

    Another tip … one from sales …

    Tell them what you are going to tell them
    Tell them
    Tell them what you told them