Dual coding in science

In 1971, Alan Paivio introduced a groundbreaking concept in cognitive psychology called “dual coding.” His idea was to combine visual stimuli with verbal explanations to enhance learning. Here, I want to explore whether we’re applying this concept effectively in science education, the various forms dual coding takes, and whether, in fact, we’ve been using it for much longer than we realise.

In some subjects, teaching techniques have been highly didactic, with learners often expected to read and then understand, or engage in problem-solving. In science, however, instruction has traditionally involved demonstrations, which could be considered an early form of dual coding. For example, when a science teacher conducts an experiment, this visual act serves as one form of coding, while their verbal explanation provides the other. More recently, we’ve seen a focus on simpler diagrams as the visual component, but in essence, dual coding is about combining verbal explanations with meaningful visual aids — something science teachers have been doing for centuries.

Let’s look at some less obvious examples. Imagine I’m explaining a piece of lab equipment. You might not immediately think of this as dual coding, but by showing you the equipment and describing it, I’m engaging both visual and verbal channels. Similarly, when I use graphs or models, I’m visually representing information alongside a verbal explanation, which is central to dual coding.

Science teaching has long involved these techniques. Even basic chalkboard drawings, when paired with verbal explanations, utilise dual coding principles. With growing interest in dual coding, some educators have broadened its definition, suggesting that representing any information in two different formats qualifies. For example, depicting a nuclear fission chain reaction with both a diagram and a formula is sometimes labelled dual coding, as it shows the concept in both symbolic and pictorial ways.

An interesting debate is whether dual coding requires simultaneous presentation of both elements. For example, what if you show something and then explain it? A common method in science is to present an intricate setup, then simplify it into a diagram to make it more digestible for students. By using consistent language across both presentations, we help students connect the real-life setup with its diagrammatic representation.

One challenge is the risk of cognitive overload. If students are asked to take notes during a dual-coded lesson, they may struggle to process both the visual and verbal information fully. Instead, encourage students to focus on listening and looking first, with time afterward to consolidate their learning through notes. Breaking dual-coded content into manageable chunks helps maintain engagement and ensures learners don’t get overwhelmed.

In the post-WWII era, step-by-step teaching became popular. In science labs, teachers would give instructions in stages, allowing students to complete each part before proceeding. This method of pacing enabled students to focus on critical moments of learning during each experiment — a technique that now falls within dual coding principles.

These methods were, in many ways, the work of early educational pioneers. Though cognitive psychology has introduced new insights, it’s essential to acknowledge that teachers were employing dual coding techniques in science classrooms as far back as the 1950s and 1960s. I’m careful not to claim ownership of any technique without recognising its roots. The advances in cognitive psychology are built on a foundation laid by dedicated educators in the past. We owe much to these pioneers, and it’s important to remember their contributions as we develop new approaches to teaching.