Dual Coding: Using Diagrams and Images to Learn Faster

Dual coding means presenting information in both words and pictures at the same time, and the research evidence behind it is strong. When your brain processes a diagram alongside a written explanation, it creates two overlapping memory traces rather than one. That redundancy makes the information far easier to recall — especially under exam pressure.

What is dual coding and where does it come from?

The term comes from the work of cognitive psychologist Allan Paivio, who proposed in the 1970s that the brain has two separate systems for processing information: one for language and one for visual images. When both are activated together, learning is deeper and more durable than when only one is used.

The Education Endowment Foundation includes dual coding among the evidence-based cognitive strategies it recommends for secondary students. It is distinct from the discredited "learning styles" idea (the belief that some people are visual learners and others are auditory learners) — dual coding benefits almost everyone, regardless of any supposed learning style, because it uses how all human brains naturally work.

What counts as dual coding — and what does not

Dual coding is specifically about combining words with a visual representation of the same information. A few important distinctions:

This IS dual coding | This is NOT dual coding
Drawing a labelled diagram of the water cycle while reading about it | Adding decorative doodles to your notes
Sketching a timeline of World War Two causes alongside written notes | Highlighting text in multiple colours (without adding visuals)
Drawing a force diagram when revising Newton's laws | Watching a video without making any notes or sketches
Creating a simple flowchart of the digestive system | Copying out text in neat handwriting

The visual element must carry content, not just decoration. A rough sketch with labels is more valuable than an elaborate but content-free drawing.

Which subjects benefit most from dual coding?

Almost every GCSE subject benefits, though the approach looks different across them:

Science: Draw cell diagrams, particle models, circuit diagrams, and food webs from memory rather than just copying them. Redrawing from recall is far more powerful than tracing.

Geography: Sketch annotated maps, cross-sections (e.g. a river valley), and SEEP (Social, Economic, Environmental, Political) webs to link case study factors.

History: Create annotated timelines of events, causes-and-consequences diagrams, and source analysis grids.

Maths: Draw visual representations of problems — number lines, bar models, graphs — alongside algebraic working.

English Literature: Map character relationships, annotate text extracts with margin notes, or draw a themes web connecting quotations.

Modern Languages: Use image-word associations (e.g. a sketch of a house next to the French word maison) to anchor vocabulary.

How to dual code your revision notes in four steps

Read a section of your notes or textbook — one topic at a time. Understand it before you start drawing.

Close your notes and, from memory, create a visual: a diagram, a flowchart, a sketch, a simple graph, or a timeline.

Add concise labels — the key terms and short explanations that make the visual meaningful.

Check your visual against your notes — what did you miss or get wrong? Add corrections in a different colour.

This process combines dual coding with active recall (retrieving from memory rather than copying). The two techniques reinforce each other and are more powerful together than either is alone.

Dual coding in practice: a worked example for KS3 Biology

Here is how a student might dual code the topic of the human circulatory system:

Written note: "The heart pumps oxygenated blood from the lungs to the body via the aorta (left side) and deoxygenated blood from the body to the lungs via the pulmonary artery (right side). It has four chambers: right atrium, right ventricle, left atrium, left ventricle."

Dual coded visual: Draw a simple two-loop diagram — one loop from heart to lungs (labelled "pulmonary circuit"), one from heart to body (labelled "systemic circuit"). Add arrows showing blood direction, and label the four chambers on a central heart shape. Mark "O₂" and "CO₂" to show where oxygen is gained and lost.

This simple sketch takes under five minutes to draw from memory and teaches the structure of the circulatory system more durably than reading the paragraph three times.

How to avoid the most common dual coding mistakes

Too much text in the visual: Keep labels short — the diagram carries the structure; a few words carry the meaning. If you are writing full sentences in your diagram, you have moved back to text-only.

Copying rather than recalling: Drawing a diagram with the textbook open in front of you is much less effective than drawing it from memory and then checking. The effortful recall is what builds the memory.

Only making the visual once: Revisit your diagrams in later sessions. Sketch the same diagram again from memory a few days later. Spacing the retrieval strengthens memory significantly.

Using it for every single topic without variation: Dual coding works best for content with clear structure (processes, systems, sequences, relationships). For some types of learning — practising essay writing or solving calculation chains — other techniques work better alongside it.

Frequently asked questions

Do I have to be good at drawing to use dual coding?

Not at all. Dual coding does not require artistic skill — rough sketches with clear labels work just as well as polished diagrams. The brain responds to the structure and relationships in the image, not its aesthetic quality. A simple box-and-arrow flowchart drawn in 30 seconds can be more effective than a carefully coloured illustration if the content is accurate and drawn from memory.

Is dual coding the same as mind mapping?

They overlap, but are not identical. Mind mapping is one form of visual note-taking that can involve dual coding if it combines images with text. However, many mind maps are text-heavy and use branching structure without genuine visual encoding. Dual coding specifically refers to the combined activation of verbal and visual memory channels — so a simple annotated sketch can be better dual coding than a complex mind map with no images.

Can I use dual coding on a tablet or computer?

Yes. Drawing apps, simple diagramming tools, or even slides with shapes and labels can all be used for dual coding. The key is that the visual is created by you — not copied from a source. Passive looking at diagrams in a textbook activates only the visual channel briefly; actively constructing a diagram engages both channels deeply.

How is dual coding different from learning styles?

Learning styles theory claims that individuals have a fixed preference (visual, auditory, kinaesthetic) and learn best when taught in their preferred style. This is not supported by evidence. Dual coding, by contrast, is about how all human brains process and store information — verbal and visual systems work together universally. It is a strategy for everyone, not a category of learner.

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