Designing slides with words and pictures

In one line: people learn more from words and pictures together than from words alone, especially when the picture is on screen and the words are spoken.

What Mayer did

This is a book, not a single experiment. Richard Mayer and his team spent over ten years running lab experiments, mostly with university students. Each experiment taught a short lesson, such as how lightning forms or how a bicycle pump works. One group got one version, another group got a slightly different one: with or without pictures, with spoken or written words, with or without extra decoration. Then everyone took a test, usually soon afterwards.

In the book, Mayer pulled the results together into a set of design rules. He explained them with a simple model: we take in information through two channels, one for what we see and one for what we hear. Each channel can only handle a little at a time. He built this on two older ideas: Paivio’s dual coding and Baddeley’s model of working memory (the small part of memory we use to think about new things).

What he found

• Words and pictures beat words alone. A picture that shows what the words describe helped people understand and use what they’d learned.
• Say it, don’t print it. With a picture on screen, people learned more when the words were spoken than when they were printed. Printed words and pictures both need the eyes.
• Don’t show and say the same words over a picture. Adding on-screen text that repeats the narration made learning worse, not better. The printed words pulled people’s eyes away from the picture.
• Less is more. Cutting interesting but unneeded extras (stories, decoration, background music) helped people learn the main point.
• Keep words and pictures together. Labels next to the part they describe, and words spoken as the picture appears, worked better than words and pictures kept apart.
• Beginners gain most. These effects were strongest for people new to the topic.

How much should you trust it?

Strong, well-repeated evidence in the lab, for short lessons; little tested in healthcare.

• Most experiments used students, short lessons and tests soon afterwards. Few checked memory a week or more later, and few were in workplaces.
• The “say it, don’t print it” and “don’t repeat the words” findings are among the best supported. But both hold mainly when there’s a picture and the speaker sets the pace. They weaken when people can pause and go back at their own speed.
• Without a picture, reading slide text aloud hasn’t been shown to do harm (Adesope & Nesbit, 2012).
• The rules fit narrated explanations best. They’re harder to apply to discussion, hands-on practice or group work.

If you need to convince someone

In our words (a paraphrase, not a quotation): students who received words and pictures learned more deeply than those who received words alone, and this held across repeated experiments.

A slide that repeats the speaker’s notes word for word, with logos round the edges, is what these rules warn against: unlikely to help memory, and with a picture on it, it may well hinder it.

What it means for you

Start with what people need to do differently. Then, in order of ease:

1. Cut on-screen text that repeats what you say. Keep at most a few key words, placed next to the part of the picture they describe (Mayer & Johnson, 2008). Put the full text in a handout or your notes. That also helps anyone who relies on text, such as people with hearing loss.
2. Pair one clear picture with your spoken explanation. The picture should show what you’re describing: the thing, the process or the link between them. Your words explain it, rather than reading out labels.
3. Strip out the extras. Logos, decorative animations and “just for context” tables all add up over a session.

How it appears in Teaching That Lands

Mayer’s work is behind Session 1’s core design rule: you carry the words; the slide carries the picture. Participants meet the two channels (“text plus voice competes, image plus voice works together”), then redesign a slide in two rounds. The second round is a readability check, because anything that makes a slide harder to read adds clutter for everyone. The “Who is this slide for?” slides also borrow a later rule, segmenting: one idea at a time, with a click for the next.

The small print

• Editions: the 2001 first edition set out seven principles: multimedia, spatial contiguity, temporal contiguity, coherence, modality, redundancy and individual differences. The well-known list of twelve (adding signalling, segmenting and others) comes from the 2009 second edition.
• Theory: Mayer calls his model the cognitive theory of multimedia learning. It draws on Baddeley (1986) and Paivio (1971). Both models have since been refined, so treat the two-channel picture as a useful simplification.
• Redundancy, revised: a review of 57 studies found that spoken plus written text was no worse than written alone, and better than spoken alone, when there were no pictures (Adesope & Nesbit, 2012). Mayer and Johnson (2008) found short key phrases next to the matching part of a diagram helped.
• Modality: the benefit of spoken over printed words shrinks, and can reverse, when learners control the pace or the text is long.