DOs and DON’Ts of scientific presentations

Every meeting brings about  few presentations for which the same mistakes seems to happen again and again. Just coming back from a major conference  in my field, I can confirm it… again. Here is a few tips that can help make your presentation better with minimal work:


Don’t use the whole real estate space just because you can. A presentation is similar to a well done document in the sense that you do want margin all around and avoid putting critical information in those margin. Times and times again you see presentations for which information are missing, such as axis label for a figure to close to the border or even the complete bottom part of the slide which can only be seen from the first few front rows.

Don’t ever fill-up the slide just because you can copy and paste from a WORD document. Even worst, fill-up the slide and read every single words on it…

Do take your time and put a single “big” idea per slide. If a figure or table convey more than one idea, copy the slide or use an animation (first approach preferred) to introduce that new idea.

Do take your time to make sure that every slide contribute to your overall presentation “story.”  If it doesn’t simplify by removing it. You want to be convincing and in that bring to audience to follow you in what should be an obvious conclusion.

From the previous two DOs, always DO start building a presentation by establishing first what will be your overall main message.

Do use precise words and short sentence(s). It is OK with having an empty slide or a slide with just an image or just a word or just a sentence. It is however not OK to have more than 45-50 words unless you are quoting some or something for a very specific purpose.

Don’t ever use fonts smaller than 24 pts. You want your slide to be easy to absorb even in that last row of the ballroom. As a bonus, this simple rule along with the use of margins will help you keep the number of words on your slide to a reasonable level 😉

Figures and Tables

That previous rule DO apply to figures and tables! Numbers and characters for axis and labels should never be smaller than 24 pts. Nothing worst than having that killer graph that 75-80% of the audience cannot even figure out because it cannot be read.

If your figure have many different data sets on it, DO alternate between open and filled symbols such as open square, black dots, open triangle, back stars, … Having x and + signs next to each other does not work.

Similarly, don’t ever use pale color for your plot lines or symbols: yellow, pale green, pink (yeah I have seen – or not – this), … This simply does not work. Black, blue, green (dark), red and combination of full, dashed, dot-dashed and dotted lines are plenty. By the way, since a good fraction of the population are color blind avoid contrasting two important data sets with red and green!

Do always present your figures, including X and Y axis before discussing the results. The time it take you to do this is also the time your audience need to figure out what is shown (if your figure is well-design based on the above rules); they are now ready to listen to what you have to say.

Don’t, never show a table that take a whole slide and have dozens of numbers. First it will be impossible to meet the 24 pts rule and second, most of the audience brains will simply shut off. My experience is that:

  1. People want to show a trend, which is better served by a well-design figure,
  2. Want to give the impression that they worked hard. Fine just say you have taken a zillion measurements but only present the relevant ones.
  3. Only a few are really relevant to the message and many times peoples will have a small animation putting a circle around those values or turning the fonts into another color or boldfaced or … These are the one you should show is a well-design table for!

Other considerations

Don’t, never use pale font colors on a pale backgrounds: yellow on white is probably the worst of them.

Do use either dark font colors on a pale background ( black on white, dark blue on white, …) or pale font colors on a dark background (white fonts on a black background or white fonts on a dark red background and so on). You get the idea.

Do use and customize you master slide. This will ensure that you have always the same size and color title fonts, place always at the same spot on the slide, …

Don’t put your logos, e-mail, URL on every slides. This “over branding” behavior does not help you as it provides sources distraction while you are trying to engage peoples.

Do use your logos on the first slide with your name, title, …

Do also use your affiliation logos, financing partner logos, URL, e-mail on the very last slide (that will stay up waiting for question). Better yet, provide the audience with a QR code which can be your VCARD, an URL to your website and so on. This is clean, non-distracting and very useful.

One last thing

Do, always take the time to make sure that your presentation will come out correctly on the conference system. Going from Mac to PC or even on PC from one system configuration to another can give you a few surprises, especially regarding animations and movies.


The above covers the very basics stuff. We go over this “design” process with the students during group meetings and in preparation to oral presentations at major conferences. More in-depth tips can be found on this post and this one.

I would really like to hear out your useful tricks and tips.


  1. Hi Luc,
    Very nice post! One addition, not so much related to the visuals of a presentation, but more on the audio:
    DON’T speak with a monotonous voice and try to alternate the intonation and volume of your voice when speaking to emphasise the important and relevant information.
    Mehmet Uzumcu


    1. Thanks Mehmet!

      Very important DON’T indeed, part of another group of tips for DOs and DON’Ts in performing an oral scientific presentation. A future post 😉



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