Most studying happens in one format: words, read silently off a page. Dual coding theory proposes that information stored in two forms — verbal and visual — is easier to retrieve than information stored in just one, because each form creates a separate path back to the same memory. If you forget the words, the image might still bring it back, and vice versa. The practical version of this isn’t about being a good artist — it’s about routinely pairing what you’re learning with some kind of visual structure, however rough.

What dual coding theory says

The idea, developed by psychologist Allan Paivio, is that the mind processes verbal information (words, sounds, language) and visual information (images, spatial layouts, diagrams) through partially separate channels. When information is encoded in only one channel, there’s only one route to retrieve it later. When the same information is encoded in both — a concept explained in words and represented in a diagram — there are two retrieval routes, and remembering one can help reconstruct the other.

This doesn’t mean visual learners exist as a fixed type and verbal learners as another — the evidence for that popular idea is weak. It means that for most people, for most material, combining the two formats beats either alone, regardless of which one feels more “natural” to a given person.

How to apply dual coding without being an artist

The visual doesn’t need to be good — it needs to capture structure: how parts relate to each other, what comes before or after what, what’s bigger or smaller, what causes what.

  • Timelines for anything sequential — historical events, the steps of a process, the stages of an experiment. A horizontal line with labeled points captures order and spacing that a paragraph of text doesn’t show as directly.
  • Simple diagrams with arrows for cause-and-effect or cyclical processes — a feedback loop, a chemical cycle, how one economic factor affects another. The arrows are the information; the boxes just need labels.
  • Tables for comparing multiple items across the same set of criteria — this is itself a visual structure, even though it’s made of text, because the grid shows relationships that a list of separate paragraphs hides.
  • Rough sketches, even stick figures or boxes, for spatial or mechanical concepts — how something is arranged, what’s connected to what.

The test for whether a visual is doing its job: could you redraw it from memory, roughly, after putting it away? If yes, it’s encoding structure. If you copied it accurately but couldn’t reproduce it, it may have been more decoration than encoding.

Dual coding for specific subjects

IELTS Writing Task 1 is, in a sense, dual coding in reverse — you’re given a chart, graph, or diagram and have to describe it in words. Practicing this skill in both directions reinforces it: when studying for Writing Task 2 or any reading passage with data, try sketching what a passage describes as a simple chart, and separately, take a chart and write out what it shows in full sentences. Both directions strengthen the same underlying skill of translating between visual and verbal representations.

SAT data interpretation questions (tables, graphs, scatter plots) reward the same translation skill — being comfortable converting a visual into a verbal statement (“as X increases, Y decreases, except between points A and B where…”) and vice versa.

Any process-based subject — biology cycles, historical cause-and-effect chains, multi-step math procedures — benefits from a simple flow diagram alongside the written explanation, even if the diagram is just boxes and arrows drawn from memory after reading.

Common mistakes

Using pre-made images instead of generating your own. A polished diagram from a textbook is easier to look at, but — as with concrete examples — generating your own version, even a worse one, requires retrieving and organizing the information yourself, which is where the learning happens.

Decorative images that don’t encode structure. A picture of a cell next to a paragraph about cell function doesn’t help much if it’s just an illustration rather than a labeled diagram showing the relationships the text describes. The image needs to carry information, not just accompany it.

FAQ

Do I need to be good at drawing for this to work? No — the diagrams that work best for dual coding are often the crudest: boxes, arrows, simple timelines. The value is in the structure and the act of creating it, not visual quality.

Digital tools or paper? Either works. Paper has an advantage for quick, rough sketches with no setup cost; digital tools help if you want to build a reusable diagram you’ll revisit. The format matters less than whether you’re generating the visual yourself rather than copying one.

How does this relate to re-reading and concrete examples? Re-reading keeps information in a single verbal format, with no retrieval required — the opposite of what dual coding and concrete examples both do. All three point to the same underlying principle: information you actively transform or reconstruct — into a picture, an example, or a recalled summary — sticks better than information you simply re-encounter in its original form.