Dual Coding
Dual coding involves presenting concepts in two different mediums or modalities, such as combining visual and verbal information. A mix of visual, audio, text, or other modes can help the lesson be more dynamic and engaging for students. However, it is generally recommended to avoid combining two or more modes of visual information, as this can overwhelm the learner's cognitive resources. Cognitive load theory, which was discussed in an earlier post, is a framework that also suggests avoiding unnecessary load on students when they learn.
Developed by Canadian Researcher Allan Pallavio, dual coding theory states that visual and audio information are processed differently in the human brain and that combining the two can enhance comprehension and retention of information. While they are separate, they can be integrated and linked to form richer, more complex mental connections and representations of concepts. This association between visual and verbal modes can be especially helpful in math education, where abstract concepts can become challenging if students cannot visualize them. For example, symbols, numbers, and geometric concepts can be taught alongside graphing software such as Desmos to illustrate the idea in real time.
One effective way to implement dual coding is through annotated visuals. Teachers can display a problem on the board and narrate their thought process as they solve it while highlighting or annotating the steps directly on the visual representation. Giving students something to follow during a lecture or explanation—whether it's a slide presentation, worksheet, or other visual aid—can help reinforce the covered concepts. When teaching the concept of slopes, a topic that can be challenging for some students but is integral for higher-level math, a visualization of how the slope changes with different lines and angles can significantly enhance the student's understanding.
Another practical method is integrating interactive software or tools that support dual coding. Platforms like Desmos, as mentioned before, or GeoGebra enable students to manipulate graphs and shapes while receiving immediate verbal feedback from instructors or written prompts from the software. Depending on how instruction is guided, students can actively engage with the material and explore the visual-spatial relationships that are foundational to mathematical thinking.
Or, storytelling combined with visuals can play a role in bringing math competitions to life. For example, when teaching probability, a teacher might narrate a real-world scenario—such as planning a school fundraiser with a raffle—and accompany the story with visuals like pie charts, tables, or tree diagrams. The narrative can provide a framework where students are actively working towards solving some real-world problem, which engages their interest beyond plain formulas with no context and allows them to apply probability concepts in a practical setting.
The diversity of dual coding means that, for students who struggle with traditional text-heavy instruction, alternative avenues may open up a door to better understanding and retention of mathematical concepts. Visual learners, for example, can thrive in an environment where diagrams, graphs, and illustrations are used to map out abstract ideas. Auditory learners can gain more through explanations and narratives that bring the material to life. For students who are English language learners (ELLs) or have learning disabilities, dual coding can reduce barriers to comprehension by presenting information in multiple formats. Dual encoding and other tailored instruction methods hold promise to be an effective strategy to support diverse learning needs and improve overall student achievement in mathematics.
