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Designing effective slides

In a talk, visual aids are just as important as verbal delivery. In this video, we give a few tips on slide design and data presentation
We’re pretty sure you have attended a scientific presentation – or a public science event, even, and were faced with the risk of sudden death by PowerPoint. What this means is listening for twenty or thirty minutes to a talk supported by slides that looked like ♪this♪, or like ♪this♪. How can we avoid this? By not pasting the entire content of our talk on the slides, and following principles derived from information design. The spirit of these principles, such as avoiding unneeded elements and clutter applies to the entire presentation, and not only to the slides.
In fact, the important thing to keep in mind is to avoid information overload – that is, to limit the amount of information that we give during a talk. In a scientific setting, we are asked to show everything, to tell everything. To discuss the methods in minute detail, and all results This is crucial in science – if we hide some results, if we don’t discuss all aspects of what we have done, we are distorting the communication. So, the first topic we would like to discuss is how to present data. There are graphical and “narrative” aspects to this.
Sometimes, narrative aspects can decide graphical ones: consider for instance this graph. If you are defining the setting of your talk by comparing the incidence of obesity in the US vs Austria, for instance, you don’t need to show all the other data points. They would give unneeded information and they can take the attention away from your message. Choosing the kind of plot should follow the
same rule: it might make sense to use a violin plot in a scientific setting, but the extra information that they carry could confuse a non-technical audience. The subject of the talk should not be your message, and not how to interpret the plot! Furthermore, some graphs are harder than others to understand, and yet are commonly used – it is the case of pie and donut charts. Both are poor at conveying information – especially when the differences between the different categories you are showing are small, like in this case. This gets even worse when you use 3D effects and tilt the chart, like this.
Purely graphical aspects are, of course, more personal, but there are simple guidelines that could help you design more effective slides. Just as we want to avoid information overload by giving too much data, we want to avoid visual overload. If a graphical element is not needed on the slide, you should remove it. This includes the reference lines in grids and tables, for instance, as well as removing separate legends from your charts and labeling your plots directly.
Colors should be used carefully, too: you can use them for labeling, to draw attention towards an element, to create contrast on the slide, or just to make your slideshow nicer. In all cases, it is better to avoid using bright colors over wide areas, or too many contrasting colors that “fight” for your viewer’s attention. If you are unsure, you can start by using a color scheme designer like the one we link under the “see also” section. Once you choose a starting hue, the color scheme designer will provide you with a few
alternatives: the main color and its complementary, which would provide the maximum contrast between elements; a more balanced approach with one main color and two contrasting ones, and others. Finally, use images to convey information. Just like stories, pictures catch your viewers’ eyes, and mind, and make it easier to remember the information you are giving. Y ou could talk about the structure of a neuron for hours, but it is almost impossible to beat the beauty and immediateness of an image like this. As they say, an image is worth a thousand words…

Some tips on slide design

Slideshows are regularly used as a tool in presentations – from board meetings to TEDx talks. However, they often are poorly designed: they include very small text, too much information, clashing colours.

This can lead to a condition that has been humorously described as “death by Powerpoint”.
However, following a few simple principles can avoid it. The advice includes things such as sticking to a single concept for each slide, using images (some free repositories include Pixabay, Unsplash and Pexels), and avoiding long blocks of text.

The way data is presented is important, too: graphs and plots should not overwhelm your audience with information, and they should not be hard to interpret.
For this reason, 3D effects should be avoided, and the same is true for pie charts and donut charts, which are not always easy to understand, especially when the audience should make comparisons.

Finally, colors should be used consistently, and with moderation. Choosing a color scheme is not always easy, but there are some tools that can guide your choices.
Color schemes designers can build a full palette starting from a single hue, and these tools are easily accessible online – for instance, at Paletton or Coolors.

The effect that your color palette has on your graphs – and on their readability – can also be assessed by using websites such as Viz Palette. Using these tools will also allow to assess whether your colours are easily distinguishable by the entire audience, including the persons suffering from colour vision deficiency, which could impact up to 10% of your audience.

Share with us

  • Were you aware of the existence of these tools ?
  • Do you agree with the graphical advice we gave in this talk, or do you believe that it could lead to presentations that look to minimalistic and standardized?

Share your opinion with us and your fellow learners in the comment section!

This article is from the free online

Science Communication and Public Engagement

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