“How many slides should I have?”
Out of all the questions I get asked by clients, either in my workshops or 1-on-1 coaching, clients asking how many slides they should have in a presentation is by far the most commonly asked.
I think this question is being asked for one of two reasons:
First: Someone has told them how many slides they should have per talk duration, often articulated as “x minute(s) per slide” and they want to know if my answer is the same.
Second: I train several technical experts on how to better engage non-technical audiences. Such professionals (and students), being trained in standard processes (experimental design, algorithms, protocols), incorporate any training into personal working blueprints to apply in future tasks. They want a rule of thumb to use when designing a talk, as they want in all other processes.
Regardless of their reason, my answer often seems to surprise, sometimes with a bit of a head-snap of shock:
“As many or as few as you need.”
This answer can be confusing or somewhat unsatisfying to those asking for the second reason. Those asking for the first reason will sometimes say “But, I was told one slide per minute!? Isn’t that a good idea?”
It really does depend. It depends on your audience – how should the information be conveyed, in what narrative arc, using what words, so they are most captivated and remember it best? I’ve given talks that have over 100 slides inside of 10 minutes. I’ve given presentations that show 0 slides.*
What sort of talk does your audience need? Design slides to that need, whatever the slide count may be.
Slide design will dictate more than anything else how many slides you have in a given presentation. Personally, my slides often have a spartan design – an image with no text or a slide with just a few words capturing the central point. I agree, like Nancy Duarte recommends, that slides should be like billboards. Indeed, see the featured image for this post.
It’s quite possible to have many dozens of slides in a short talk, because you’re not spending much time on each slide. It’s also possible to have only a few slides, perhaps three or five, introduced as thematic backdrops for each portion of the talk.
I also recommend to technical speakers presenting in front of direct colleagues that only showing their technical figures, with no text leading in or out, can make for a better talk: if your talk’s purpose is to discuss recent data, only show that data. This might only need a single slide (often a graph) for an entire talk. Put audiences first.
Audiences first design means you very deliberately think about how to guide the audience through your presentation.
When you are designing with an audiences first mentality, the number of slides you end up are those that you find best convey the information. Slides may come and go as you write, edit, and practice – some ideas might work spread across several slides while others are doable in one, or even none.
If you’re trying to fit a set amount of content into a “x time per slide” rule, audiences-first design almost always goes out the window.
I was told once that NPR reading speed is 2 words per second. By this logic a “1 minute per slide” means you can put 120 words of text onto the slide and it’s completely allowed. Which of the two slides below do you find most effective?
The minute you spend on the first slide is a minute in which the majority of your audience will mentally check out … and you might never get their attention back.
So put your audiences first when it comes to slide design and have as many, or as few, as you need for a captivating talk that’s memorable. If you find it difficult to create slides without using a lot of words, maybe you’re actually writing a handout, which I’ll come to in another post.
Now, how ma
*A zero slides talk is of course a presentation with no slides. However it’s arrived at differently: if the instruction is “your presentation can have no slides” then that’s a framing rule . But if you’re free to choose, you might find in the crafting that really you don’t need any slides to get your point across. Perhaps your slides are even distractions from what you’re trying to say – they distract the audience away from you or they distract you from the audience because of a particular delivery style you’re going for. Just because the option for slides exists does not mean you have to exercise that option. Put audiences first when designing your talk – only show what the audience needs to pay attention to your point and remember your ideas. Use all the tools of presentations at your disposal.