What dual coding describes

Allan Paivio’s dual-coding theory distinguishes verbal representations from nonverbal, image-based representations and explains how they can connect in memory. Spoken and written words are both linguistic input. A diagram can show spatial or visual relations, but “nonverbal” does not simply mean everything on a screen. Paivio’s account of the theory and Clark and Paivio’s education review describe these representations and their links.

The theory is not a basis for sorting students into fixed “visual” and “auditory” learner types. Ask whether a purposeful image explains the same idea as concise language. An image is not instructional just because it is present.

A hypothetical lesson and a check

Suppose you are teaching blood flow through the heart. Sketch the four chambers, add arrows for direction, and put short labels such as “right ventricle → pulmonary artery” beside the relevant arrow. If you add narration, explain the relation as you trace the flow; keep captions or a text equivalent available. W3C’s media-accessibility guidance explains that captions convey speech and meaningful non-speech audio for people who are Deaf or hard of hearing. Accessibility is not a reason to remove a needed text route as “redundant.”

Hide the diagram and ask students to state the flow, then give them a different heart diagram and ask them to map it. The first check tests recall of terms; the second checks whether the relation transfers to a new layout. This is a practical classroom check, not a guaranteed outcome of the theory. Avoid forcing abstract ideas into inaccurate pictures or crowding a diagram with labels.

Sources