Dual coding: study with words and your own drawings

Dual coding means studying an idea in words and in a visual form at the same time: a diagram, a timeline, a graph or a labeled sketch. What makes it useful in practice is that you draw it yourself and can later rebuild it from memory along with its explanation.

A quick example: reading that “evaporation moves water from the ocean into the atmosphere” leaves you with a sentence. Drawing an arrow from the sea to a cloud, labeling it “evaporation,” and explaining what energy drives it gives you two routes back to the same idea. If one route fails on the exam, the other may still get you there.

Clark and Paivio (1991) set out dual coding theory and its implications for education. The theory holds that we process information through a verbal system and a nonverbal, image-based system, and that ideas engaging both tend to be remembered better. The authors reviewed studies in which concrete, easy-to-picture words were recalled better than abstract ones.

Keep the claim in proportion. Dunlosky and colleagues (2013) reviewed imagery use for learning from text and rated it low utility, because the benefits appeared mostly with texts that were easy to picture and on tests given soon after studying. Dual coding is also not about having a “visual learning style”: the idea is that any student can combine words and images when the content allows it.

Not every topic is drawn the same way. Before you open your notebook, ask which relationship you need to remember: a sequence, a comparison, a quantity that changes, or a structure with parts. The format should show that relationship, not decorate the page.

Topic: the water cycle. You draw a sea, a cloud, a mountain and a river. Arrows: from the sea to the cloud, “evaporation”; inside the cloud, “condensation”; from the cloud to the mountain, “precipitation”; from the mountain into the ground, “infiltration”; down the slope to the river and the sea, “runoff.” You add an arrow from plants into the air labeled “transpiration.” The whole drawing fits on half a page.

Underneath you write three sentences: energy from the Sun drives evaporation; water vapor condenses into droplets as it cools; water that does not soak into the ground flows over the surface. The image and the explanation are now linked by the same labels. The example is our own and simplified; your course may expect more, such as groundwater or sublimation.

A diagram copied from the textbook works a lot like rereading: comfortable, and it checks very little. The next day, take a blank sheet, redraw the diagram without looking, and explain each arrow out loud or in writing. Then open your original and mark in a different color what was missing or in the wrong place.

That comparison is where you learn the most. If you remembered the drawing but not what one arrow means, the gap is in the relationship, not the image. If you remembered the sentences but put a stage out of order, the sequence needs work. Repeat the exercise a few days later with only the parts you missed.

A beautiful diagram can eat an entire afternoon and teach very little. Before you call it finished, check that every visual element answers a question from your syllabus and that you could explain it without the textbook.

In Lumia AI you can generate a draft set of flashcards and quizzes from images as well as from text and PDFs. Upload a photo of your labeled diagram as the source, then review each question and rewrite any that only ask for a name so they ask about the relationship instead, for example: “What happens to water vapor when it cools in the atmosphere?”

You can also create cards by hand and add an optional hint, such as “think about the arrow leaving the cloud.” During review, answer before you flip the card and rate it Again, Hard, Good or Easy. Generation from a photo can misread handwriting or small labels, so compare the draft with your drawing before you study it.