Should you read your slides? The “Mayer Myth” busted!

Some people are adamant you should never read your slides. Why? In part, because of research by Richard Mayer, author of Multi-Media Learning. But his research has been misinterpreted and misquoted, turning into the “Mayer Myth”.

In his famous study, he found students learned better when a speaker used picture slides than when the same speaker used text and picture slides. The implication: when the speech and text are identical, remove the text from your slides – called the redundancy principle

Some people have interpreted this to mean never read your slides. But that’s not Mayer’s point. It only applies when you’re using pictures to illustrate what you’re saying. For instance, if you’re explaining how lightning forms, just show the process on slides and narrate it with your voice, rather than adding the exact same text to the slide.

In fact, Richard Mayer makes this explicit on page 159 of Multi-Media Learning:

“The redundancy effect should not be taken as justification for never presenting printed and spoken text together….Presenting words in spoken and printed form may be harmful in some situations – such as in the studies described in this chapter – but not in other situations – such as when the rate of presentation is slow or when no pictorial material is concurrently presented. For example, it might be useful to present summary slides (or to write key ideas on a chalkboard) in the course of a verbal presentation or lecture. This is a research question that warrants further study.”

I’m sure future research will show it harms learning to read paragraph-length text from your slides, or read from a dense forest of 12-point bullet points, or turn your back to the audience to read your slides.

But we may also learn that it improves learning to read 5-6 word bullet points, or a long sentence that is broken into lines of 5-6 words each, over using no text slides at all.

So let’s not misquote poor Dr. Mayer, the way we’ve misquoted poor Dr. Mehrabian. Dr. Mayer’s research only applies to slides with pictures that the speaker is describing.

In fact, he explicitly says just the opposite: you probably can use text to outline and summarize your talk.

So let’s stop spreading the “Mayer Myth”.

About the author: Bruce Gabrielle is author of Speaking PowerPoint: the new language of business, showing a 12-step method for creating clearer and more persuasive PowerPoint slides for boardroom presentations. Subscribe to this blog or join my LinkedIn group to get new posts sent to your inbox.

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7 Responses to Should you read your slides? The “Mayer Myth” busted!

  1. Jakob says:

    Bruce, I commend you for sticking up for research. However, while Mayer correctly refers the question to future studies there are two well established factors that work in favor of shunning reading the text on your slide altogether for people who want to err on the side of caution:
    1. managing attention spans – people read faster than you speak. Period. There are times where you want to reinforce a message through repetition, but unless you know how to do that on purpose, why make yourself unnecessarily vulnerable to boredom?
    2. managing attention – all language input is eventually processed by just one area in your brain that is unable to multitask. Try following two conversations at the same time – you are guaranteed to understand less in either than when you followed just one. It does not matter if the input channel for language is visual or verbal, in the end you are forcing people to multitask rather than focus on one type of language input. Not good.

    keep up the good work,

    • Hi Jakob – Thanks for the comments. I agree that if you want to err on the side of caution, avoid reading your slides. And I agree with your points on attention, but I don’t think that rules out slide text in all cases.

      1. If the points are short, it isn’t harmful that you’re breifly out of sync with the audience reading your slides and it will help the visual learners.

      2. Managing attention is not always better for the audience. People learn best when they control the pace of their learning. I remember I was once meeting with a sale person who was trying to explain a complex fianancial product to me. He wasn’t making any sense so I picked up his handouts and began reading. The handout answered my question better than he did. So, in situations where the speaker isn’t making much sense, crisply worded text slides will help keep them from rambling, or provide the necessary clarity when they are rambling.

      • Jakob says:

        Hm? The wordpress email notification seems to have failed me.

        I’ll have to disagree with you that managing attention is a bad thing for your audience. If your message is not clear then its best to remedy that problem rather than place the burden on your audience to deduce it from other material. Polishing your message first and then your delivery to a point where uptake is a breeze should be the goal of every speaker. Your finance guy obviously fell short on both accounts.

        I do agree with you that text on slides is not a bad thing per se. My point is that reading it out aloud is only warranted on very few occasions. Or rather that you should know why certain rules of thumb exist in the first place to know when to brake them on purpose.

      • I’m planning to write a larger blog post on the issue of managing your audience’s attention. I’d be interested in your reaction to that when it’s posted.

  2. Franco says:

    Dear Bruce and Jacob,

    the issue is not as much as managing attention, but as managing cognitive load,

    Cognitive load theory is much more complete than Mayer’s multimedia learning theory.

    I doesn’t offer to you some rigid “don’t do that” principles, but a comprehensive guidelines to understand what would happen in YOUR specific situation, and this depend on: 1) the content; 2) the cognitive/learning task; 3) the level of expertise of the people who attend the presentation.

    In particular, the expertise reversal effect says that “designs and techniques that are effective with novices can lose their effectiveness and even have negative consequences when used with more experienced users.”.

    See for ezample Clark, Nguyen and Sweller, Efficiency in Learning, Pfeiffer 2006


    • Franco says:

      I doesn’t offer -> It doesn’t offer

      sorry for my English 🙂

    • Welcome to the Speaking PowerPoint community, Franco!

      I agree with you. The issue is not as simple as ALWAYS or NEVER. It does depend a great deal on the complexity of the material being covered, the audience’s motivation to pay attention, the design of the slide (elegant or cluttered) and many other factors. Cognitive Load Theory provides some guidelines to help us make educated decisions.

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