Dual Coding: How Combining Words and Visuals Deepens Learning

One of the most robust and practical findings in the science of learning is also one of the simplest: combining words with relevant visuals produces better learning than either words or visuals alone. This is dual coding, and unlike the discredited learning styles theory, it is well-supported and applies to essentially everyone. Understanding it changes how you should take notes, study, and present information.

The Theory Behind Dual Coding

Dual coding theory, developed by psychologist Allan Paivio, proposes that the mind processes information through two distinct but connected channels: a verbal channel for language and a visual channel for images. Crucially, these channels are somewhat independent, each with its own processing capacity. When information is encoded in both channels — as both words and a visual representation — it creates two complementary memory traces rather than one, and either can be used to retrieve the information later.

This is why a concept learned as both a verbal explanation and a diagram is remembered better than the same concept learned as text alone. You have stored it twice, in two forms, with two routes to recall. The two representations also reinforce each other, deepening understanding.

Why It Works: Two Channels, More Capacity

Working memory has strict and separate limits for verbal and visual information. Presenting everything through one channel can overload it, while distributing information across both channels uses the brain's full processing capacity more efficiently. This connects dual coding to cognitive load theory: well-designed combinations of words and visuals can convey more without overwhelming working memory, because they draw on two pools of capacity rather than one.

The benefit also comes from the richer encoding. A visual representation captures spatial relationships, structure, and patterns that words describe only awkwardly, while words capture precision, logic, and detail that images cannot. Together they represent information more completely than either alone, producing deeper comprehension.

The Important Caveat: Relevant, Integrated Visuals

Dual coding works only when the visuals are genuinely relevant and meaningfully connected to the verbal content. Decorative images that do not carry information provide no benefit and can even distract, adding load without adding meaning. The visual must represent the actual concept — a diagram of a process, a chart of a relationship, a spatial map of a structure — not merely illustrate the topic loosely.

The visuals must also be integrated with the words rather than separated. When related text and images are placed apart — a diagram on one page and its explanation on another — the learner must split attention to connect them, which creates cognitive load and undermines the benefit. This is the split-attention effect. Dual coding delivers its benefit when words and relevant visuals are close together and clearly linked, so the two channels reinforce rather than compete.

How to Use Dual Coding in Your Own Learning

Add visuals to your notes. When taking notes, do not rely on text alone. Draw diagrams, flowcharts, timelines, and simple sketches that represent the relationships and structures in the material. Even rough, hand-drawn visuals engage the visual channel and deepen encoding. The act of creating the visual also forces you to process and organize the information.

Translate between forms. A powerful dual coding practice is to take verbal information and represent it visually, or take a visual and explain it in words. This translation forces genuine understanding — you cannot diagram what you do not understand — and creates the dual representation. Turning a text explanation into a diagram, or a diagram into a written explanation, is active, effortful learning.

Use concept maps and mind maps. These tools naturally combine verbal content (the words at each node) with visual-spatial structure (the layout and connections), embodying dual coding. They are especially effective for capturing how ideas relate to one another.

Seek out or create good diagrams. When learning complex material, look for clear visual representations — well-designed diagrams, charts, and models — to accompany the verbal content. Where none exist, create your own. Studying a good diagram alongside the text produces better learning than the text alone.

Keep words and visuals together. When creating study materials, place explanatory text directly with the relevant visual rather than separating them, so the two channels reinforce each other without forcing you to split attention.

Dual Coding vs Learning Styles

It is worth distinguishing dual coding from the learning styles myth. Learning styles claims that individuals should receive information in their single preferred mode. Dual coding says the opposite: everyone benefits from engaging both verbal and visual channels together. It is not about catering to a personal style but about using the brain's dual-channel architecture, which is common to all of us. Dual coding is one of the evidence-based techniques that the learning styles myth distracts people from.

Conclusion

Dual coding — combining words with relevant, integrated visuals — produces stronger, more retrievable learning than either alone, because it engages the brain's two processing channels and creates complementary memory traces. Add diagrams to your notes, translate between verbal and visual forms, use concept maps, and keep words and visuals together. Unlike the learning styles myth, dual coding works for everyone, because it exploits an architecture we all share. When you want to learn something deeply, do not just read about it or just picture it — do both, together.

Further Reading

• Allan Paivio, foundational research on Dual Coding Theory
• Yana Weinstein & Megan Sumeracki, Understanding How We Learn (2018)