I was chatting with Louis about how to give good presentations, and revealed that I’d written up a checklist of things to avoid in giving statistics presentations. Here it is, with details underneath. It is written in the dictatorial style of Strunk and White. Von Bing provided comments on an earlier draft.
- Landscape orientation?
- Margins not excessive?
- Non-informative contents page?
- Too many slides?
- Too many words?
- Font large enough?
- Colour visible on projector?
- Spelling checked?
- Are you sure you want every equation?
- Do the equations come out ok?
- Are you sure you want a table?
- Limited to 2 significant figures?
- Decimal places lined up?
- Only relevant entries tabulated?
- Too much information for one slide?
- Fonts large enough?
- Axes labelled?
- Labels big enough?
- Margins too big?
- Excessive space between figures?
- Colour visible on projector?
- Lines and points labelled, e.g. on legend?
- Can plot cover whole slide?
- Don’t read from the slide
- Be aware of colour blindness
Some detailed thoughts:
1. Landscape orientation?
It’s a good idea to make sure your slides are set up so that they are wider than they are tall, i.e. that they have a landscape, not portrait, orientation. Modern (post-1990s?) projectors project landscape orientation. If you use portrait, your slides will cover only half the available surface area, meaning that everything is smaller than need be.
2. Margins not excessive?
Some slides are formatted to have a “double margin”, that is, a space, a line, another space, and then content. This may or may not be to your taste, but in any case, it wastes space and, again, means the content of the slides is smaller than need be.
3. Non-informative contents page?
If your talk is very short, e.g. 15 minutes, it’s debatable if you should have a contents page at all. But if you do have a contents page, it is advisable to use informative headings. If your contents page says “Introduction, Methods, Results, Discussion”, it will convey no real information (of course you’re going to start with an introduction!) and may irritate the audience.
4. Too many slides?
It is always wise to plan in advance to have the right number of slides for the length of time you will be talking. You don’t want the chair to stop you when you are half way through discussing the methodology and still have 47 slides to present. You might develop contingency plans that allow you to skip parts if you find you’ve spent too long at the beginning, or to spend more time discussing if you’ve got time to spare. LaTeX beamer is great for this, as it allows you effortlessly to put hyperlinks to different sections of your talk in the margin, thus allowing you to skip slides without having to flick through them, hence revealing the bad planning to the audience.
5. Too many words?
You may wish to avoid putting too much text on a single slide. The audience, when faced with a slide full of words in a small font, will either have to ignore you while they read it, or won’t read it. And if you recite the content of the slides to your audience, again, they will probably just ignore you and focus on the words on slide.
6. Font large enough?
You should ensure the font is sufficiently large that people at the back of the room with bad eyesight will be able to see it. To check this, try putting your slides on a projector and then standing at the back of the room or a similar room (get someone with bad eyesight to help if need be). If it seems too small, it is too small. Making the font large enough will additionally ensure your slides don’t have too much text on them.
7. Colour visible on projector?
Bright fluorescent green text might look great on your computer monitor, but the chances are it won’t be visible on the projector. It’s recommended to check out the colours at the same time you check the size of your fonts.
8. Spelling checked?
Use a spell checker. Do this even if you are a native anglophone (or whatever the language of the conference). Do this especially if you are not.
9. Are you sure you want every equation?
It takes a lot of concentration to understand an equation, especially if you are not familiar with the details of the topic. Furthermore, if yours is one of a series of talks, the audience will probably forget your notation before you have finished using it. (In fact, I usually forget notation even in individual seminars.) For these reasons, you ought to think very carefully about whether or not you really want each equation. Can the equation be replaced by a pithy description or (ideally) plot? Does it even contribute to the message of your talk?
10. Do the equations come out okay?
There are few things that show a speaker’s lack of respect for his or her audience than seeing an equation that has been mistyped in LaTeX by a speaker who hasn’t even checked its final appearance. To avoid this is simple: check that your equations come out the way you intended before the talk, not during it.
11. Are you sure you want a table?
Many statisticians love tables. Tables can be a powerful tool for presenting a message. But they require work to get right. So many talks I have been to have been let down by ill-thought out tables, obstreperous and crammed full of numbers that reveal no message. I implore you: think carefully about each table you include in a presentation. Can a graph convey the information instead? If so, use the graph.
12. Limited to 2 significant figures?
Wainer (1997, J. Ed. Behav. Stat. 22:1–30) should be required reading for all statisticians. Do not use more than two significant figures in a table in a presentation.
13. Decimal places lined up?
Make sure you’ve lined up decimal places.
14. Only relevant entries tabulated?
You may be copying a table from a paper of yours. The paper probably contains a lot of information in the table. During the presentation, you probably don’t want the express every single gram of information in that original table. If so, a simple solution is not to put all that information in the table. Take out anything that you’re not going to talk about. If this is difficult to do, you can always highlight the bits you plan to talk about, so the audience can concentrate on them and ignore the other clutter.
15. Too much information for one slide?
If you do wish to talk about many points on a table, you might break the table up over several slides, as this will make it easy for the audience to digest.
16. Fonts large enough?
As with text, make sure the font size in the table is large enough for everyone in the audience to read easily.
17. Axes labelled?
Always always always label axes. Always.
18. Labels big enough?
Many statistical packages have defaults settings that are wholly inappropriate for graphics for presentations. Typically, these are set up for you to print the graph on a large piece of paper and pore over with a magnifying glass at your leisure. If you make all labels much bigger than they are by default, this will endear you to your audience.
19. Margins too big?
Similarly, most packages put excessive amounts of white space around the graph. One really should cut this down, so that the margins are big enough for your enlargened labels but no bigger.
20. Excessive space between figures?
If you have more than one panel on a figure, it is likely that much of the figure is covered by blank white space between panels, making everything else smaller than need be. This unnecessary space can easily be cut down.
21. Colour visible on projector?
Colour helps graphs tremendously. Except when it is bright yellow on a white background.
22. Lines and points labelled, e.g. on legend?
Are all lines and points labelled? If not, please remember to describe them to your audience. Better yet is to label them and describe them to your audience. A nice technique if you are using a legend is to ensure that the uppermost line in the legend corresponds to the uppermost line on the plot and so on down to the lowermost.
23. Can plot cover whole slide?
If you have a single plot and no text on a slide, nothing is lost by enlargening the plot so that it covers the whole slide. So why not do this?
24. Don’t read from the slide
This suggestion is more for students. Don’t read from the slide. The audience can read the slide themselves (unless the font size is too small or a badly chosen colour, see above).
25. Be aware of colour blindness
About 5% of the men, and a smaller proportion of the women, in your audience are likely to suffer from colour blindness. Use colour considerately: if you choose to use colours in a graphic (which is probably a good idea for getting the message across to the majority), please also point to the red and green lines (say) so that the colour blind will know which ones you mean.