Why do most people think it's a bad idea to read from slides?

Question

As many of you probably know, almost all advice regarding doing better academic talks includes universal advice to not put too many words in any one slide, and to not read straight from slides (this is always thought to be a sign of a bad talk).

I used to agree with all of this because it sounds reasonable, and anyway that's how I've written my own talks so far. But I went to a conference late last year where a speaker did exactly the opposite of this advice (my field is mathematics). He was literally reading his slides verbatim, and each of his slides was packed full with long sentences. And yet, it was one of my favorite talks of the conference, and for me (a Ph.D student) it was clean, clear, and easy to follow despite the fact that the material was completely new to me. I do think a large part of the reason I found it so clean and clear was precisely because of the talk's structure, and not despite of it.

That experience made me rethink my prejudice against speakers who read out of the slides. For some people, it may be a superior talk strategy to alternatives, especially in academic fields where the details really matter.

So, I am not convinced anymore that it is general (or even, usual) good advice to not read from the slides. Why do people think it's such a bad idea? And please don't say "it's lazy" or "could just read the slides instead of listening to the talk" because in practice, neither of these perspectives demonstrate why an alternative is better at communicating the information, which is what really matters.

Answer 1

Research in the field of multimedia learning suggests that in most cases, "people learn more deeply from graphics and narration than from graphics, narration, and onscreen text". This is known as the redundancy principle.

Previous research has shown students learn better from multimedia lessons containing graphics and narration than from graphics, narration, and redundant on-screen text (Kalyuga, Chandler, & Sweller, 1999, 2000, 2004; Leahy, Chandler, & Sweller, 2003; Mayer, Heiser, & Lonn, 2001; Moreno & Mayer, 2002a, 2002b; Mousavi, Low, & Sweller, 1995). This finding is known as the redundancy effect (Mayer, 2001, 2005c). For example, in a study by Moreno and Mayer (2002b), participants viewed an animation about lightning formation. The first condition had narration accompany the animation, whereas a second condition received redundant on-screen text in addition to the animation and narration. The group that received the redundant on-screen text performed worse on subsequent retention and transfer questions than did the group that received animation and narration; thus, a redundancy effect was found.

(source: [1])

Why?

Adding redundant on-screen text detracts from the learning processes highlighted in Figure 1 because it creates extraneous processing—such as inducing the learner to visually scan between the caption at the bottom of the screen and the graphic and to try to mentally reconcile the incoming spoken and verbal stream. If the learner has to waste limited cognitive capacity on extraneous processing, the learner will be less able to engage in the cognitive processing needed for learning—essential and generative processing.

(also from [1])

Are there times when it is good to include some of the narration in a slide? Yes. For example:

The most straightforward contribution of this work is to add an important caveat to the redundancy principle “People learn more deeply from graphics and narration than from graphics, narration, and onscreen text” (Mayer, 2005c, p. 193). In revising this statement of the redundancy principle, we can add the following limitation: “except when the on-screen text is short, highlights the key action described in the narration, and is placed next to the portion of the graphic that it describes.”

(also: [1])

In a meta-analysis of the literature on the redundancy principle:

[A]dvantages of spoken–written presentations over spoken-only presentations were found for low prior knowledge learners, system-paced learning materials, and picture-free materials. In comparison with verbatim, spoken–written presentations, presentations displaying key terms extracted from spoken narrations were associated with better learning outcomes and accounted for much of the advantage of spoken–written over spoken-only presentations.

(Source: [2])

You perceived the talk with redundant written and spoken text to be beneficial to you; this is consistent with the research as well:

Research on metacognition has consistently demonstrated that learners fail to endorse instructional designs that produce benefits to memory, and often prefer designs that actually impair comprehension. Unlike previous studies in which learners were only exposed to a single multimedia design, the current study used a within–subjects approach to examine whether exposure to both redundant text and non-redundant text multimedia presentations improved learners' metacognitive judgments about presentation styles that promote better understanding. A redundant text multimedia presentation containing narration paired with verbatim on–screen text (Redundant) was contrasted with two non-redundant text multimedia presentations: (1) narration paired with images and minimal text (Complementary) or (2) narration paired with minimal text (Sparse). Learners watched presentation pairs of either Redundant + Complementary, or Redundant + Sparse. Results demonstrate that Complementary and Sparse presentations produced highest overall performance on the final comprehension assessment, but the Redundant presentation produced highest perceived understanding and engagement ratings. These findings suggest that learners misperceive the benefits of redundant text, even after direct exposure to a non-redundant, effective presentation.

(Source: [3])

Note that the results above refer to multimedia presentations, i.e. those that include graphics. Presentations that do not include graphics may benefit from redundant spoken-written text (see [4]). But presentations that do not use graphics violate the multimedia principle, which states that in general, "people learn better from words and pictures than from words alone".

For more information on principles of multimedia learning, see The Cambridge Handbook of Multimedia Learning. If you're looking for something shorter, here is a brief summary of the major principles of multimedia learning, and here is a presentation by Richard Mayer.

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References:

[1] Revising the redundancy principle in multimedia learning. Mayer, Richard E.; Johnson, Cheryl I. Journal of Educational Psychology, Vol 100(2), May 2008, 380-386. http://dx.doi.org/10.1037/0022-0663.100.2.380

[2] Verbal redundancy in multimedia learning environments: A meta-analysis. Adesope, Olusola O.; Nesbit, John C. Journal of Educational Psychology, Vol 104(1), Feb 2012, 250-263. http://dx.doi.org/10.1037/a0026147

[3] Learners misperceive the benefits of redundant text in multimedia learning . Fenesi, Barbara; Kim, Joseph A. Frontiers in psychology 5, 2014. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4088922/

[4] Verbal redundancy in multimedia learning: When reading helps listening. Moreno, Roxana; Mayer, Richard E. Journal of Educational Psychology, Vol 94(1), Mar 2002, 156-163. http://dx.doi.org/10.1037/0022-0663.94.1.156

Answer 2

I have worked both in pure math (topology) and very applied math (discrete optimization in logistics).

Much of the usual advice on "using only graphics and very little text" applies well to the applied fields where there is actually plenty to visualize and the theoretical machinery -- at least the part you introduce in the talk -- is not that deep.

In pure math, though, you often have so much notation, definitions and complicated lemmata that it is very hard to keep the slides clean. Furthermore, the speed of talk is often so high that losing attention for 30 seconds might be enough that you cannot follow anything anymore.

Nevertheless, people usually get bored by someone reading to them. While it might be a good idea to put some reminders on the slides to help people follow complicated and abstract stuff, it is not really advisable to read everything aloud.

Answer 3

There are a number of good answers here, but I think there is a point that hasn't been so much emphasised.

On the one hand, the general/default rule is - don't read from slides, make them compact and keyword oriented.

However, the OP belongs to what I believe is a special class of listeners: they are a mathematician and they are (making an educated guess) still young and ambitious to learn a lot quickly. I remember myself preferring very detailed slides when I was not yet acquainted with the spectrum of techniques in the field and still curious about learning details. This is precisely the target group for very detailed slides (although, frankly, a blackboard talk, in this case, is even preferable if at all possible).

And no: not for everybody reading a paper/handout has the same effect as a talk - even with the precisely same content. A good speaker can emphasise and highlight in a way a written text doesn't.

In short: if your topic requires attention to detail (speak: mathematics or theoretical physics, mostly), and you speak to a very eager, but still inexperienced audience, you may consider reading from slides (if they - the slides - and you are very well prepared). If you speak to an experienced, or only moderately curious audience (which is the norm), stick to the default strategy. Or else, go for blackboard.

Answer 4

BLUF: Being better than just reading the slides is a necessary condition for a talk to be worth giving. (being something different than reading slides, however, is not a sufficient condition)

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As a listener, in my opinion, a talk that is nothing more than displayed text with a live reading is pretty much the single worst method for communicating written information I have ever experienced.

In this format,

• I cannot read and digest information at my natural pace
• I cannot go back to review prior material
• I cannot skip ahead to get an idea where the content is heading to
• I cannot search
• I cannot interrupt the talk if I want to work something out in the middle
• I cannot bring other materials to study along with the information in the talk
• I cannot sit in a comfortable chair in an air-conditioned room while consuming the content
• I have to deal with interruptions from others, any difficulties the speaker has speaking, and potential difficulty simply understanding the speaker's speech

If a talk has nothing to offer beyond a live reading of the written word, the talk shouldn't be given, and instead the written content should be made available in a convenient written form.

I will grant your point that you can give talks that are worse than just reading slides. However, those talks shouldn't be given either.

Answer 5

When reading out loud, we (subconsciously) speak faster and with less intonation changes than when speaking directly. This makes the talk harder to follow and makes it much more likely for the audience to zone out. Yes, the presenter can fight this and read like they would speak normally, but it takes constant conscious effort on their part, and is easy to forget especially when stressed, running out of time, etc. (Notice that a similar thing applies when the talk is learned word-for-word by heart, which is also normally discouraged).

A block of text on a slide also occupies the listener's attention more; it's basically enticing the listener to read it. And if the presenter ever says something else than exactly what is on the slides (such as inserting a personal anecdote, a last-minute thought, a clarifying point), the listener can actually lose on that precisely because their mind is still focused on reading.

A slide with short bullet points also allows the listener to quickly glance it over as soon as it first appears, and gain a brief understanding of what the talk on this slide will be about. Just like we normally give an outline of the entire talk at the start of the presentation to help the audience understand where we'll be going and why, a bullet-point slide can serve as a mini-outline of the talk for that slide. It's always easier to follow a talk if you know where it's going⁽¹⁾.

Far be it from me to say that a presentation cannot be good (or excellent) if it consists of paragraphed text which the presenter just reads. But it requires much more skill from the presenter to keep the talk interesting and not lose their audience. This can be part of the reason why general advice is to do bullet-point slides; the average presenter is more likely to give a better presentation with that. Of course, the expert presenter can do what they want and what they know best, and they can pull it off. But until you are the expert, it's safer for you to work "the easier way." It's similar to other areas: when you start, you're best off following the common rules. Then you master them, and eventually you understand them and the subject enough to know when you can break them for the better.

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⁽¹⁾ I have a personal anecdote to illustrate this (which may of course not be applicable to everyone). At university, when a math lecture had a theorem to teach, it generally followed the structure of "state the theorem, present the proof." One lecturer took an opposite approach: he would basically start with "Let us have group G. Let us have another group H. Let us define an isomorphism ..." He would present the proof first, and end with "... now we can see that H must be a subgroup of G." He would then formalise this into the theorem. For me, these were the absolutely hardest lectures to follow; it was next to impossible to keep track of where the ramblingproof was going without knowing what the goal was.

Answer 6

In addition to the counterproductive effect on the audience, when someone projects text and then reads it, I get the impression that he doesn't know it very well. Especially if, like some I've suffered through, he reads it sounding like someone else wrote it, i.e. as if it's new to him.

Answer 7

I have attended several conferences, all in English and material-based, and there was always a slides-reader.

They have in common:

• English wasn't the speaker's native language, and they had problems speaking.
• Poor pronunciation, monotonous voice. Some were reading the values in tables!
• The slides were poor quality. Wrong colours, light serif font, low-resolution images.
• Slides overwhelmed by full sentences with few images and graphs.
• Awkward discussion time with one simple question, usually asked by chairman, and "Sorry, no understand" answer.

When reading from slides or from notes, the speaker usually have a monotonous voice and no contact with the audience. A good presenter adapts their speech to actual attention and the content, which is much harder when reading and a lot easier when talking offhand.

Personally, when someone reads it all loud it gives me impression that they cannot speak the conference language or their knowledge of the field of their presentation is not good. Some people are too nervous to speak offhand, but it is quite easy to distinguish them.

I was taught that presentation is dedicated to sell the results and attract the audience. For further exchange of ideas there are discussions, breaks, articles and letters.

Answer 8

The short answer is "Because most people who do it do a terribly poor job presenting". You certainly can give a good talk this way but you have to think about 1 hour about what you want to put on each slide that will be on the screen for 3 minutes or so and then a few more hours about how to put them together. And since the result you get this way is pretty rigid, you should know your audience really well to make sure that the exposition is neither too boring, nor too fast for it. I've seen good "slide reading" talks too (the speaker didn't rush at all, used the capabilities of the beamer to make sure that even on each given slide, which was one full logical unit easy to digest, the sentences would appear one by one as the exposition went, and made sure that each next sentence or formula was both clearly related to the previous ones and containing some new idea or twist), but they were like 1 out of 30.

Most good speakers prefer to use slides just to emphasize a few crucial points and to improvise with how to say everything else depending on the questions they receive from the audience, etc. It just saves time on preparation and gives more flexibility to the speaker.

This ability to improvise, however, is also a skill and if there were plenty of poor improvisers, the advice might be exactly the opposite: put everything on slides in advance and try to stick to them. However, as it happens, poor speakers are usually afraid of improvisation and have a false belief that doing things meticulously and in order can save an otherwise doomed presentation (doomed for many reasons, the top of which are being aimed at a completely wrong audience and requiring way more time to do properly than allotted), so we just do not see many bad improvisations, but plenty of terrible but meticulously prepared talks and a good portion of those are the ones by slide readers.

Answer 9

Almost all of the talks I attended were in English while I'm not a native English speaker. Yes, I can read the words faster than the speaker talks, but I can't understand as fast, and definitely not when someone is talking about something else. By reading it out, the speaker gives me more time to digest, which is very helpful.

The main point is that you don't put EVERYTHING you want to say on the slides and read word for word and nothing else. Have some bullets points, read them out one a time, then expand each one vocally.

So write your slides clearly and concisely, then by all means, read the slides, and talk much more than that.

Answer 10

The question is why I think it is a bad idea. In my case, I have attended over the years to a fair number of talks by "slide readers" and they were all atrocious (and boring).

I can imagine the possibility that a lecturer reads from very well-prepared slides and make a decent talk. But in all good slide-talks I have attended, the slides had very sparse, concrete and specific information that was complemented by the speaker's speech.

Answer 11

People have this idea that there is a one-size-fits-all rule for giving a presentation. There is not, and I know this from having taught the subject in the real world for 6 years. I have critiqued every sort of imaginable presentation, from sales, chemistry, accounting, updating, etc. When a car salesman is "doing his thing" he is giving a presentation. When a magician is "doing her thing" she is giving a presentation. When a 15 year old is "doing her thing" with mom and dad she is giving a presentation. The audience is different in each example, as is the presenter. Most of the answers here are from the presenter's point of view, which is the usual selfish way presenters go about boring their audiences. "What do I need to do?" is the question most presenters start from. You need to do the opposite. Let me explain.

In general, it's a "bad idea to read off of slides" for a number or reasons. But then, who is the audience, and why is reading off the slides bad for that audience? If a car salesman read the brochure in front of you then it is "bad to read off the slides." However, at a math lecture It might not be "bad to read off the slides." I wasn't there, so I can't say what made this particular speaker's presentation good (or possibly "bad."). It seems you learned something, and thought the presentation style worked.

The kind of presentation you give depends on the audience. Let me say that again: the style of delivery you use depends on the audience. It depends on their purpose for watching and paying attention. There is no one-size-fits-all rule because there is no one-size-fits-all audience. The examples I gave above should make that clear. Ask yourself, as part of your preparation process two questions: what is my purpose and what is their purpose? There are always two purposes in any presentation. If you're just updating on some progress, then reading off the slides might be fine. If you're trying to persuade then it's best not to have a lot of info on the slides so that the audience can focus on you, and you can focus on being persuasive, which works much better when people aren't distracted. But then, if you are trying to persuade your audience that you have found a proof for the Goldbach Conjecture, then you're going to have lots of slides with lots of stuff...the audience won't expect less.

Part of learning is copying the teacher. The next time you give a presentation, do what you saw last time. Does it work? If so, try it again and again to see if the reason it worked wasn't luck but something else. If it doesn't work, then you will have to explore and find your own style that fits the particular audience to which you are presenting. The path to presentation excellence is through trial and error. There is no other way. In Ancient Greece and Rome, students spent years practicing the art of debate and presentation, and then went out in public to persuade others. The situations were real and oftentimes matters of life and death or stability of the state, so if you sucked at presenting it could cost you dearly. By the way, before I forget, what worked then, won't work now. Why? Because the audience is different.

BTW, let me add that at the end of your question you make a comment about "communicating information." Without context and purpose, information is useless. This is why most presentations are a waste of time. They are wastes of time because many presenters see themselves as information ambassadors or messengers. They don't give context, purpose, or meaning to their information. They expect the audience to "get it." This is a bad hope to have.

So to summarize, the question of whether it is bad to read off the slides is really a question of whether it is bad to read off slides for your particular audience. There is no general answer or golden rules on this. Ask yourself what the purpose of the audience is and go from there.

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Answer 12

I am reluctant to add yet another answer to an already crowded page, but I feel there is an important point that has not been made (apologies if I've missed it).

Different people (even within the same discipline) have different preferred ways to absorb information. Some may take things in best by reading, some through engaging talks. It sounds as if OP may fall into the first camp. If all were the same, then we could probably dispense with talks and just read each others' papers, followed by a Q&A session. But this would be a great disservice to those like myself who find it easier to concentrate on listening to an engaging speaker rather than reading a block of text.

The bottom line: it would be wrong to say that "reading the slide" is a poor way of communicating per se, but it is a poor way of reaching a sizable proportion of the audience. Perhaps we should all consider how we can make our presentations appealing to both (or indeed all) types of audience member.

Answer 13

Basically, people tend to get bored when you read text at them.

If you are going to just read them, the lecture becomes like a sort of audiobook of a paper. Or just a normal book, with a lot of noise distracting you.

The thing with books is you can blaze through the easy parts and slow down on the hard bits. You can leaf back and forth to remember bits you forgot. You control the information stream, and the text is prepared with this assumption. That's why it works.

In a slideshow, you don't control the slides. If you need extra time for a given slide, well, too bad. If you need to have understood that slide to follow subsequent slides, too bad. Everyone will find a different part difficult, so it's hard for the presenter to "just slow down on the hard parts". You end up with a Poisson distribution of "number of slides before the presenter loses them" over audience members, few make it to the last slide without getting lost.

Also, people tend to pay attention less when someone isn't engaging the audience. It's psychological. When reading slides, people look down or away (at the screen) and don't make eye contact with the audience. The audience does not get the psychological cue that "somebody is talking to me" and gets distracted more easily. Also, many people who do this slide reading seem to quickly fall into a monotone, droning tone that's even harder to stay with.

Not reading slides gives you freedom in pacing and managing your presentation in real time. If you are very good, you can actually watch the audiences reaction and adjust the presentation accordingly as you go. Since often at least some part of the audience is not terribly interested in the presentation to begin with, being more engaging helps maintain their attention (if that sort of thing matters to you).

ff524 has compiled a nice bibliography of the research. But here experience can also suffice: Think back to the presentations you've seen. Which ones were the most effective? Which ones were the most boring? Do you see a pattern of correlating presentation styles? What about your peers (after all, you are not presenting for yourself)? Don't just look at one case, look at the general picture. Perhaps in your field, reading indeed does work better (for instance, I think for poetry or literature it can), or maybe the people who like to read slides just happen to be much better presenters otherwise. Or maybe this one talk was an exception, and otherwise even you find most slide-readers tedious to listen to.

I have seen very few slide-readings that weren't boring. It doesn't help that often, it seems that people who do it are bad presenters to begin with, so they are making two errors. Presentations I enjoy, especially if we adjust for topic, are overwhelmingly ones with free-form talking and minimal slide reading. Likewise for presentations I've given and how well they were received. Thus, based on my experience, in my field, I try to avoid slide readings because I have personally seen it to be a poor choice. Your experience may be different, and thus also your conclusion.

However, as I said above, there is a fundamental reason (audience cannot control flow) why slide readings will necessarily be worse than their closest relative, the audiobook and the written book. Whether they can still be made to be as good as a more engaged presentation, is for you to decide.

Answer 14

The obvious effect when reading slides verbatim is that slide and narration are redundant. Why that's bad depends on how you as an audience member are trying to follow the presentation:

• If you are just following the narration, the text on the slides and switching between the slides will unnecessarily distract you.
• If you are just reading the slides, the speaker's voice will unnecessarily distract you.
• If you are both listening to the speaker and reading the slides, you'll have to constantly keep both in sync, which increases your cognitive load, especially when you get distracted just for a second and then have to find the correct position on the slide again.

All of these lower your chances of understanding the talk. These effects don't happen if you have simple slides that supplement the oral presentation.

Answer 15

From my experience of years of teaching young learners to make presentations; the reasons why a presenter should not read the slides are:

1. It is a waste of time, because the audience can be given a handout with that information.

2. Making a presentation is knowledge sharing. A slide is only a visual aid to support what you say as a presenter.

3. The audience is educated, they can read it for themselves.

4. Reading aloud to some people can be rather boring. It is not interactive, and the key word in any presentation is "interactive".

5. Generally you put the bullet points, supported with graphics or pictures and then share your knowledge and view on whatever is in the slides. They are there to support what you want to say.

This is my opinion based on what I have learnt and taught over the years.

Answer 16

Expanding on jf328's answer, "reading slides" can be helpful if you have an audience that struggles with the language you are presenting in or has problems with low literacy despite natively speaking the language of the presentation. Here's an article that mentions adding an audio track to a written presentation to enhance comprehension by people with low literacy.

Whether or not any of these situations apply is going to be very contextual. At a major international conference with attendees from throughout the world, reading skill may be an important issue and something that you cannot simply presume exists (or exists at a sufficiently high level for your presentation). At a university lecture with students who have all passed the university's required literacy test for enrollment, providing an audio version of the slides "just because" could be seen as patronizing.

Answer 17

I won't go into the reasons that you normally should not do overly verbuous slides; you already know about them.

But on the presentation that you liked so much: If the presenter simply read exactly the contents of his slides, then they were not so much slides but a kind of subtitle. If he was obviously consistent in it, then every listener was free to read the slides or not; or only read the slides and not listen; or listen and read at the same time.

The bad thing about text-rich slides crop up when the presenter does not just read them verbatim. Then you as a listener have to chose between listening and reading; and it is very easy to get confused. This has not happened here.

Answer 18

It's about using the right tool for the job.

There are a variety of mediums and methods to convey information (written material, multi-media, human presenter, etc.). Each has strengths and weaknesses for different kinds of information, and a role to play.

Highly technical information and tons of facts can be absorbed by the recipient looking at written or visual materials at their own pace. A human presenter can be helpful, but more so with "high level" information than extensive detail. For example, relating the gist and concepts, or providing a framework the recipient can use to organize the information they subsequently read on their own. (I'm referring to a presentation scenario rather than a highly interactive educational setting.)

If a human presenter is simply reading the slides to the audience, the slides become the presenter and the human just their A/V aid as an annoying soundtrack. Why not just have an automated slide show, or even one with a recorded soundtrack if the recitation aloud is so important? What is the human adding to the process? The biggest value provided by a human presenter is the human interaction.

The recipient's ability to absorb and retain information is tied to emotion (their interest and desire to focus on it, the personal value of the information, the novelty of it, and the strength of emotions associated with it that affect retention); it's the role of the hippocampus in learning.

That applies to any information, including technical content. The recipient needs to want to acquire the information (and have a framework for organizing it); it isn't useful to simply dispense it in their direction. If the recipient is already interested and motivated, a human presenter can either add to, or detract from, the presentation's effectiveness.

The role in which a human presenter can uniquely contribute is to engage the audience, tapping into their attention, receptiveness, and emotions to get them involved and invested in the material. That's done through the human connection, using rapport, conversational language, vocal cues, body language, movement, animation and excitement, adding tidbits of interest, etc.; focusing on and talking to the people comprising the audience, rather than reading and providing audio for the slides. Conveying high-level information in this manner is the reason to have a human presenter, and the real value they can add.

The practice of someone present for the sole purpose of reciting material displayed on slides is even counter-productive. It can make the audience less receptive to the information than just giving them the materials to read (for the reasons described in the answers by ff524, J. Fabian Meier, Hurkyl, Angew, Crowley, WGroleau, Robert Buchholz, and Superbest).