Should I reveal my slides bit-by-bit when giving a presentation/lecture?

Question

In the comments on this question, there were a two opposing opinions (anti, pro) on the technique of revealing slides bit-by-bit, rather than all at once. The argument against doing so was that revealing slides bit-by-bit is "micromanaging" viewers' attention and that some people prefer to have access to all of the information on the slide before starting to process it. The argument in favor was that revealing a whole slide at once gives too much information, making the talk difficult to follow.

What are the pros and cons of these two approaches? How should I choose which one to use? Are there recommendations from authoritative sources and/or supported by reliable evidence? I'm mainly interested in technical presentations in science or mathematics, including both lectures to students and research talks to peers. There may also be diversity issues (dyslexia, ASD, etc.) that are relevant.

I think this question may be closely linked with the issue of how much information to put on each slide. If you have a slide that just consists of a few short bullet points, then I agree that there's not much point in revealing them one by one. But for technical presentations, one often has slides that have more information than one can reasonably take in at once.

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This was one of several questions asked here but none of the answers there seems to address this particular question.

Answer 1

You have to compromise between the three following aspects:

• Every change/transition on your slides demands some of the viewers’ attention. Mind that this is purely about the change, not the content that is eventually revealed or there from the beginning. It is easy to underestimate this as the presenter, since changes you have control over are much less demanding and you do not need to follow your own speech in parallel. This is particularly bad for people with attention disorders who may be severely distracted by every visual change.

• Whenever you reveal a new slide, it takes some time for the viewer to process the content to the extent that they can orient themselves on the slide and can follow your talk again. The time and mental strain of this process increases superlinearly with the amount of content on the slide.

  Keep in mind that humans can only have a handful of things on the top of their brain at once and half of that is already occupied by things other than your slides. When somebody sees a new slide, they first have to break everything down into processable chunks. When the number of things they visually distinguish exceeds the number of free processing slots, processing of your slides becomes considerably more difficult.

  Greying out some content (as suggested by another answer) only mildly ameliorates this: While greying something out is a visual cue that it can be ignored for a while, the viewer still has to process that cue and the greyed-out content is present and thus distracting all the time.

• Managing the reveals distracts you from speaking and otherwise affects your talk, usually in a negative manner, e.g., by making you read your slides and dropping gestures and similar. In particular, while I have seen quite a few talks with quick bullet-point-wise reveals, I have not seen a single one where the speaker did not stumble over this, i.e., mistime a reveal or lost their flow of talking.

My general rules of thumb are therefore this:

1. Only split slides if revealing the entire slide at once is visually overwhelming and splitting considerably ameliorates this.

2. However, first consider whether there is any need to have the information you present on the same slide to begin with.

3. Do not split a slide if you do not spend at least twenty seconds on either side of the split.

A good example of this if you have two plots with a shared axis where you first explain the first plot (spending twenty seconds before the split), then the second plot (spending twenty seconds after the split), and then explain how the two plots relate to each other (thus having a reason to have both plots on the same slide).

If Points 1 and 3 of the above are in conflict with each other, you are almost certainly doing something else wrong, e.g., not properly explaining a plot or having useless stuff on your slides.

Answer 2

I like to use beamer with \setbeamercovered{transparent}, as in this talk for example. Then the bits of the slide that I haven't got to are visible but greyed out. I think that this has the advantages of both the options mentioned in the question.

In more detail: the linked talk was prepared using LaTeX with the beamer package. The preamble starts like this:

\documentclass[9pt,xcolor={usenames,dvipsnames}]{beamer}
\usepackage{beamerthemesplit}
\usetheme[headheight=0pt,footheight=0pt]{boxes}
\setbeamercovered{transparent} 
\setbeamertemplate{navigation symbols}{}

The fourth line says \setbeamercovered{transparent}; this is the option that ensures that some parts of the slide are greyed out rather than being completely invisible. Transitions between different states are created using a mixture of the commands \pause, \uncover and \only, which are explained in the package documentation.

Answer 3

This is a personal view, but with long experience behind it. I think the answer should be different for things like classroom lectures and conference presentations.

For classroom lectures, I suggest that you give the students access to any slides a day or two in advance. This permits those who have the inclination to look them over prior to the lecture and think about questions. It also permits them to print out the slides and annotate them during the lecture as a form of note taking. The purpose of such a lecture is learning and this can enhance it.

A conference presentation, on the other hand, is a kind of performance. Few people (some) will take detailed notes during the talk and the flow can be important. Also, such lectures are normally given to those with a lot of field experience already, so insight is more valuable there than detail. A friend of mine was brilliant about using things like PowerPoint to present very dynamic presentations that didn't actually need a speaker to present commentary. The presentation was complete in itself. I never had such skill.

But, consider both the purpose of the lecture and the nature of the audience. The best solution may well depend on those factors.

Answer 4

No. What you should do is refrain from using your slides as speaker notes. Your slides should have 2 purposes: 1) to pique your audience’s interest in what you’re about to say and 2) to help them remember what you did say.

Compare these 2 slides:

Which slide would result in the audience spending time reading instead of listening to you, the presenter? Which slide would tend to make them more interested in your presentation?

Note: This isn’t a lesson on good slide design. I don’t think it’s arguable the second slide is better than the first. It is. It’s also not arguable there are more improvements we could make to the second slide to make it even better. The point I’m making here is to not put so much information on your slides that they’re effectively useless.

Now to the original question: “Should [you] reveal [your] slides bit-by-bit when giving a presentation/lecture?” That’s up to you. I said “no” initially, but it’s really up to you. It’s neither an absolutely good technique nor an absolutely bad technique. For presentations I deliver, I use that technique more often than not. In the example above, it may be advantageous to reveal first only the title, then the Positive Gz Effects, then the Negative G. Effects. It just depends.

Information on the slides from FAA Advisory Circular 91–61, February 28, 1984

Answer 5

Giving a talk is absolutely about managing your viewers' attention, and perhaps micromanaging it.

Every viewer has their own listening goal and learning style. But you have to give the same talk to everyone at once. So you more or less have to keep the audience's attention and understanding in sync with each other. At each point in the talk, you should have a plan -- not for controlling an engaged audience's attention, but for offering clear guidance on how they should direct it.

• If you are speaking a key point, they should mainly be paying attention to your words. The slide's visuals should assist without distracting.

• If they are reading text on the slide for more than 2-3 seconds, or thinking about a deep concept, or reading a plot carefully, etc., you should probably be mostly silent. Any comments should assist without distracting.

So the key principle is do not ask the audience to split their attention. People will split their attention different ways and nobody will get the complete picture.

• Don't reveal a large detailed slide while speaking continuously. People will try to read it and tune you out, or give up on reading it and not get any use out of it.

• Don't reveal portions of a slide rapidly while speaking continuously. Every transition takes people more time and attention to process than you think. People will miss what you're saying, or fall behind.

In general, going slowly and pausing gives people space for both autonomous thinking and following your cues.

Answer 6

There is no one right answer to this, because presentations are so different from each other in purpose and content. Rather, what can be answered is, at least in part, how can you tell which approach fits your presentation?

First question is: is the content critical to understanding the presentation? Could someone have you on audio only and still get the gist? If they could, then hopefully your content is relatively minimal and distraction-free, aimed at giving people who are more visual learners some signposts to help them along. Non-critical information lends itself better to the reveal-slowly approach, while critical information is better to leave up the whole time as different viewers will have different timing needs.

Second question, how much information is on the slides? Information dense slides can distract the reader from hearing the audio, as many people don't listen as effectively while they're reading. On the other hand, information light slides may be quickly consumed and lend themselves better to being up on the screen at once to avoid distracting the viewer with movement - unless that movement is helpful for signposting.

Third question - do you plan to release the slides to the public? Slides that will be released to the public should be created in a way where they are useful without any animations. As such, design them from the beginning to work in the all-at-once approach. Many users will view in a format that doesn't support animations (or doesn't support it easily) like PDF or still images, and instead will want to just see one particular slide to get information from it - even if there is animation support they won't appreciate the time it takes to scroll through the animation.

In the business world, I think you'll find that slides tend more towards the "animation" side, because the content on the slide itself isn't as important - the speaker is more important. In academia, in particular things like Math or Physics, the information is much more critical on the slide - the equation, the proof, that sort of thing - and as such lends itself less to doling information out in small bits. I tend to find that the first question is the deciding one for me most of the time, as a result.

Answer 7

Quod licet Jovi, non licit bovi.

Some people are good enough at presentations to make otherwise-bad approaches succeed brilliantly. Steve Jobs' slideshows broke every rule and were amazing. Doing this takes perfect timing and meticulous digital choreography, as well as a heaping helping of inspiration. And it's usually brittle: if you break your rehearsed flow (e.g. for questions), it's hard to get it back.

If you have any doubt whether you're that good, assume you aren't and stick with the basics. The benefits of fancy techniques are marginal, especially compared with the benefits of good fundamentals.

If you need to ask on here whether you should do it, the general answer is "no".

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That said, if you have a specific use-case where you are confident it will be helpful (something like successive overlays on the same data), AND you are confident you can pull it off, it's a fine technique to use occasionally.

Answer 8

One aspect I've not seen mentioned yet is that an important factor is whether the points are naturally sequential or not. Stepwise revealing works best if:

• The points have a natural ordering such that it is useful to have digested one before moving on to the next
• Each step is "meaty" enough to warrant at least 10-20 seconds before the next point is revealed
• It is meaningful to have consecutive steps on the same slide (see Wrzlprmft's plot example)

Block revealing works best if

• The points are an unordered list, ideally of minimal-text bullet points (see afwing's example)
• The entire list can be taken in as a single glance and the eye doesn't actually have a sudden wall of text to track through
• The points are not narrative or entirely self-explanatory (again, keyword bullet points help here) as you don't want to lose your audience because people are simply reading ahead in your own presentation (they can read faster than you can speak, after all)

The third option, when you have large, non-bite-sizeable points that are however not a natural sequence, is just to dedicate a slide to each (perhaps after an introduction where you explain that you will be showing several examples and their overarching connection) - much less visual clutter and better focus on a single concept at a time.

Answer 9

I agree with most of the points presented. The slides are NOT your notes and if giving the slides out to the audience is of any value to them, there was too much detail in the slides. The slides help guide you through your presentation, enabling you to add, remove, or rearrange talking points without have to memorize (and forget) the changes, which also lets you customize the presentation for different audiences - but you still need to know the material without need notes, the slides are cues for the presenter.

For the audience, the slides gives them something to focus on, gentle reminders of what you have said or are about to say, and also a visual of new or confusing terminology so they don't have to ask you for clarification. But the slides should not tell the entire story, in fact, they should whet the appetite for your presentation. There should be no value in handing the slides out to the audience.

As for the reveal technique, that depends on the presenter, the audience, and the material. I've presented to certain groups multiple times and learned that there are "hecklers" (people who disrupt your presentation with any motive, good or bad) that will ignore your order of presentation and interrupt you during bullet #1 with a question about bullet #6. For that group, I reveal one bullet at time. Other times, I'd reveal the entire list just to prevent individuals from asking "What about X?" which is bullet #6.

If you don't know your audience, follow your gut, develop your style of delivery and run with it. If you choose to reveal bullet-by-bullet, learn how to expose the entire slide at once in case there is a revolt. In the end, you want the audience to appreciate your presentation without having to battle them, but you also need to get your message across and maintain control of the presentation or you will have chaos.

Answer 10

It depends on how you structure your talk. A slide deck designed to not have animations would be prepared in such a way that slides are easily navigable to begin with. The ultimate example of this is a paper handout - there is a wealth of techniques around organizing static text on a page so as to make it readable. If you bluntly add animations like reveals to this, it would be like trying to read a book and seeing one word at a time.

Conversely if you design a talk with revealing in mind, the slides are probably too confusing when you get the full version "in your face". So simply removing the reveals would lead to a confusing, overly busy presentation. To give another analogy, imagine that instead of watching a video you had an array of every frame.

I think your first step should always be to figure out what your audience likes. Are you able to tell if they like reveals or not? How have they reacted to past presentations? If you have an audience who hates reveals, it's pointless to use them regardless of their merits. They'll be primed to dislike your presentation just on that very fact. Why stack the deck (hah!) against yourself? Just give them what they want.

If you're not aware of any clear audience preference, it's a pros vs. cons type situation. Basically you pick the problems you want to have vs. the ones you want to avoid.

No reveals

• Your slides can't be too complicated - you really need to stick to "one point per slide"
• Lots of points with corollaries or tangents is probably not good - it will confuse the audience
• The deck is easier to manage - one page is always one slide
• Timing is easier because you have fewer time points to remember (just the slide changes)
• Because you are probably thinking of something like "x minutes per slide", you have more leeway in sometimes going a bit over or under time for an individual slide, so you are more flexible on time (good if eg. audience likes to interrupt with questions)
• Interruptions are generally easier to handle, especially when people ask you to skip a section or go back to past slides
• Printing slidesheets is more straightforward and doesn't use as much paper

Judicious reveals (a few, but not too many)

• You can get away with slightly more complicated/convoluted points in each slide - it's still a good idea to make sure every slide has one point, but you have more leeway
• Managing the slides is a bit harder (not much harder, because you wisely avoided "a lot of reveals") since you have more frames and have to deal with the reveal logic and duplicated content on top of everything else
• Timing is more critical - you have only seconds per frame, so if you go over (or end up starting late!) it easily derails the whole timetable you had
• Going back or skipping slides is more annoying and distracting to the audience (since they see you flipping through animations, sometimes stopping at the wrong frame)
• The presentation is hard to keep track of. With programs like powerpoint, you can't see at a glance how many steps an upcoming slide will have. If you go the Latex route and make each frame an individual page in the PDF, you now end up with things like 100 pages for a 20 slide presentation. Audiences tend to glimpse the large number as you set up and start panicking.
• Printing is annoying - either you just accept needless duplication or you have to somehow print a subset of pages every time

Why not a lot of reveals?

I would say realistically you are picking between "no reveals" and "a few reveals".

The extreme of the animation spectrum would be to make a whole movie that you talk alongside, like a science documentary. Without even getting into pros/cons, making a movie would obviously be too impractical for just one talk, and it requires a lot of specialized skill.

Similarly for reveals and other animations, the more you use them, the more overhead it adds to the work of preparing the deck. Lots of animations makes sense if your talk will have a wide audience - like a TED talk that you're sure will go viral and get watched millions of times. But not if it's a one-time thing for a few hundred people.

Answer 11

This may be style-dependent. My own style is such: I sometimes like to give a presentation like a mystery-plot, and not have 'spoilers' for the big conclusions.

However, in general, a rule of public-speaking [e.g. from "Toastmasters"] is to:

• Tell them what you will tell them (intro / contents)

• Tell them (body)

• Tell them what you told them (summary / conclusion).

It's hard to see how one can avoid 'spoilers' in such a scenario!

As to partially revealing what is on a slide, if one uses this technique, use your verbal words to correspond with it, so that it makes sense to the audience. I.e. when new info is on the slide, start talking about it. This would then make the new slide-info into a "I'm talking about this now" marker.

The more important the presentation, the more one should stick to the fundamentals, as per Fectin's (and possibly other people's) answer.

Answer 12

If you have a slide that just consists of a few short bullet points, then I agree that there's not much point in revealing them one by one

I have the exactly opposed opinion. If you have a few short bullet points, you can reveal them one by one to keep a "thought path" for the viewers.

If you have more details on the slide (which I do not like but sometimes you have to) then I warn the audience beforehand that the slides are a reference, that they will have them and that I will just use a tiny part on them. In such a case, when you switch your slide, everyone is not frantically reading.

Answer 13

I will usually avoid doing a sequential bullet-by-bullet reveal, and that's because I try to avoid my slides and my talk saying exactly the same thing.

Now, I'm aware that there's an accessibility benefit in conveying exactly the same message in two different forms (written and spoken), and if that's what you want to do, then there's an argument for keeping the two streams synchronised, so people get the message in both forms at the same time.

But personally, as a listener I find talks where the speaker reads the slides boring; and as a speaker, I hate being constrained by my slides because it eliminates all spontaneity. So I like to use slides that complement what I'm saying rather than repeating it verbatim. I might talk about general principles and have a slide that gives a concrete example: I will say "and there's an example of that on the slide", and give people a few seconds to read the slide, while not actually talking about the example at all.

So it's a personal thing, and it depends greatly on how closely you want your spoken words and your visuals to duplicate each other.

Answer 14

There are two issues here:

1. Your slides should only have about as much text as a notecard, with just as much respect for grammar
2. The appearance of text on the slide shouldn't be distracting.

I find that if you have 1 down you rarely need to have individual transitions for elements of your slide so 2 is a non-issue. A notable exception being question/answer patterns.

For an extremely pathological case: don't use the feature for individual transition animations for bullets on a slide. It is very distracting and many students stop using it even in high school.