Hi again! A few weeks ago I wrote the first post in a series about Delivering Presentations, which covered an introdution to the theme. Today, the series continues with Part 2: Structuring your presentation slides.

Let’s review the basics

Here are three questions I raised in the last post:

  • How much time do you have for the presentation?
  • Who is the audience?
  • How is the place?

Now as I said, this information can often be determined (or estimated) beforehand and should be used to guide your presentation preparation.

The time of the presentation is of crucial importance as it will determine how much information you will actually be able to deliver. Remember humans have a limit on the amount of information they can process over a certain amount of time (i.e. they can only process a certain density of information).

This is what happens when you feed the audience with a high density of information.

Whatever the time you have, the presentation should always move from the less specific to the more specific, which means that less time will usually means less detail. There is no point in trying to explain the details of what you are proposing if you cannot first present the big picture. And the information should be presented in such a pace that allows the audience to follow you, rather than having you drag them with you. A rule of thumb that has generally worked well for me is that each slide should occupy on average 1 minute of you talk, i.e. for a 15-minute talk, prepare around 15 slides.

Instead, feed them with chewable drops of information and allow them to slowly digest it.

Make sure you tailor the content of presentation according to your audience. Delivering a long speech on the motivation for your approach to an audience who already knows of the problem you are addressing will make them fall asleep. It is nice to try to convince everyone that you know what you are doing, but often the audicence is already convinced about that and you don’t need to repeat this information.

Finally, it is not always possible, but try to determine how is the space where you will be delivering your presentation. If you can face the screen while talking and can use a pointer, maybe you don’t need to add special animations to you slides to highlight specific points. On the other hand, if you will be constantly facing the audience, it is important to use visual guidence in the slides (i.e. colors or highlights). It will also affect the size of the fonts that you need to use (larger rooms mean larger fonts, since the listeners may be further away).

Structuring your Presentation Slides

A presentation is not about showing the audience every detail of your technique. I know, as a former Ph.D. student and a continuous learner we tend towards wanting to show everything we have done and squeeze that into that 15- minute talk. However, that is not the goal of a presentation. You should answer the same questions a paper answers, but remembering that readers have only a limited time to grasp your ideas.

Structure your slides in a top-down way, from an overview to a detailed view of your work. Show them the motivation for your work. Show them the general view of your field, and where your contribution stands. Introduce your contribution. Focus on one example. Show then the results, and the conclusion of your work.

Remember, however, the time constraint I described above and try to adjust your talk accordingly. If short on time, which is very often the case, I usually remove first the complex details and then the long motivation. People WILL ask about the details you didn’t mention, but they won’t ask you about things you already tried to explain (and failed) in your talk. One strategy that generally works well is provoking the audience to ask the exact questions that you want them to, and preparing a few backup slides to address those questions.

DOs and DON’Ts in your Slides

DON’t: abuse of text

Let’s face it: it is very difficult to read something on a screen while simultaneously paying attention to what someone else is saying. You are presented with a slide full of text and your brain immediately goes into confusion. Should you focus on reading the text, or on paying attention to the speaker?

Let’s do a simple math. It is said an adult human can read about 250 words per minute. That means you put 50 words in a slide and it’s already 12 seconds the audience has to pay attention to whatever you wrote in there, instead of paying attention to you.

Instead DO: use keywords in your slides

We cannot be 100% focused on an activity for 100% of the time. Eventually, your attention will deviate. Your phone vibrates, your neighbour is speaking too loud… “oh and I don’t like when people do this, there was this on time when.. And who sent me a message? Is it important.. oh damn, what was the speaker saying?

In order to avoid this sort of problems, place keywords in your slides to guide a possible got-distracted-just-woke-up listener into what you are currently talking about. It should not repeat what you are saying, but give a context onto what you are saying. So limit the text in your slides to the key points you are addressing, and leave the connection between these points to your speech.

DON’T: abuse of figures

You read the previous section and just thought of getting rid of all text and just filling your slides with beautiful figures, didn’t you? Ok, I’ve done this in the past, so please don’t blame me. I’ve learned. What happens when you put a lot of figures in a slide is that 1) your figures will get really small and 2) you will be stuck with presenting a huge density of information in a single slide which will only confuse the audience. Slides packed with figures are very common, but the problem with them is that figures are usually so tiny that no one in the audience will be able to read them.

Finally, don’t include in the slides figures you won’t be speaking about. You don’t need to be comprehensive in your examples. Just show that you are ready to explain things further in case questions arise.

Instead DO: use a single, well-explained figure

There is a lot you can speak about just a single plot you present, and many people usually forget about this. When someone sees a new plot for the first time, it is usually not obvious what is being shown on the x/y-axis, what are the different colors, points, and so on. Show a single picture (say a plot), carefully explain what is being shown and what the consequences and key take-away of that.

Some researchers even take this approach to the extreme and argue for something called assertion-evidence approach, which in its essence consists of delivering a single statement (the assertion) along with visual-based evidence supporting that (you can read more about that here. While I wouldn’t go as extreme as that, the key take-away message here is that a lot of information one can deliver using one simple figure.

DO: give an outline of your talk …

… if your talk is long. Prepare the audience for what they are about to see, so they don’t get lost as to where you are going. Come back to that outline as you move between sections, to position the audience as to where you are at the moment. But be reasonable, no need to do it every other slide.

Now this can be tricky at first. It happened to me a few times that while I was explaining the outline, I wanted to explain why I structured the outline that way, and by doing that I was actually explaining the work before it even began. If that happens, it is probably because your outline is getting too deep into the work. The title of your work should already give the audience an idea of what to expect, now with the outline you just need to show them there is paved way towards what you want to show them, and for them to hold tight in the process.

DON’T: give an outline of your talk …

… if your talk is 5 minutes long. Seriously, that is not enough time for any human being to get distracted from your presentation, unless it is really boring. Please refer to the above-mentioned points if that is the case.

Delivering your talk

The last post in this series will be about strategies to actually delivering your talk. How to make it more insteresting, how to make the audience follow you, what you can do “at run time” to improve the quality of your talk. Stay tuned!