The Science of Learning: Dual Coding
By Ulrich Boser of the Learning Agency Lab
Lauren Mueller, an English teacher at Douglass High School in Memphis had a revelation. By simply modifying the way her class used graphic organizers, she noticed immediate improvements. She noted that it was exciting “to see kids who maybe struggle in other areas feel like, ‘Yes, let me tell you what I think.’”She also added that incorporating this new strategy into her classroom was not a big task to add to her workload. The learning strategy that Mueller used to such great effect is called dual coding, and it can change the way you teach—and learn.
What Is (and Isn’t) Dual Coding?
At its core, dual coding is simple and intuitive. The theory is based on the idea that our minds process visual cues and verbal information separately and simultaneously. In the context of learning, that means that materials that combine words and images are especially effective. By presenting the same information in two different formats, learners have more to call on when they try to remember the information later.
For educators, dual coding provides a way to improve student learning and engagement with material by providing them with more than one way to understand and remember what they’ve learned. For a while, conventional wisdom said dictated that everyone learns differently, and some people are visual learners while others are verbal learners. Educators were encouraged to adapt their lessons to better teach to multiple learning styles and improve learning outcomes. The problem is there isn’t any actual evidence to support the idea of distinct learning styles.
By contrast, dual coding doesn’t lock learners into any specific learning modalities. Rather, it takes what we already know about how our brain processes different types of information and applies it to learning. Just as importantly, it’s backed up by decades of scientific research. So, while some students might prefer visual over written material, it doesn’t mean that teachers need to convert all of their lessons to images and videos. With dual coding, learning materials use a combination of the visual and the verbal, and students learn better because of it.
Why Does Dual Coding Work?
Dual coding relies on the fact that the brain automatically associates visual representations with verbal and vice versa. For example, if you hear the word apple, you’ll probably have an image of a shiny red fruit in your mind. Likewise, when you see a bowl of apples, the word “apples” will jump into your mind.
Similarly, while reading books, most people have mental images of the characters and setting. The dual coding explains why that is. Different types of cues can be used to tap into things that we remember. Verbal cues can spark visual memories, and visual cues can spark verbal memories, while many cues spark both. Research suggests that dual coding in learning provides both verbal and visual cues to associate with a memory, making it easier to recall.
In one study, students were taught how to use a bike pump with one of four methods: 1) animation demonstration of operating the pump 2) verbal narration 3) animation with narration 4) no instruction. Not surprisingly, the group that received no instruction performed worse on the retention test than all the other groups. However, on the problem-solving test, the group that was taught with animation plus verbal instruction performed the best.
Another study challenged students to assemble toys using pictures, written instructions, or a combination. Again, the combination of visual and verbal instruction provides improved learning outcomes compared to the students learning with a single media type.
The evidence here is clear. Dual coding works, and when used correctly, can give students a learning advantage. According to learning scientist Dr. Megan Sumeracki, “When used well, combining those can provide two ways of remembering the information . . . We tend to learn best when we combine multiple modalities together.”
Dual Coding Integration
As Lauren Mueller experienced, incorporating dual coding into the classroom does not need to be a heavy lift. Even when presented with separate visualizations and text materials, students have the ability to integrate the two into a consolidated concept. For example, when a student reads a passage about photosynthesis then later sees a separate diagram of the process, they can automatically make the connection between the verbal and visual representations of the same concept.
Many materials used in everyday classrooms can be used. Written materials can be supported with visuals while visuals material can be described with words. Materials like labeled drawings, infographics, videos, or slideshows with subtitles or audio narrations are all simple ways to bring dual coding into the classroom. Even the addition of symbols or icons to text materials can help support this type of learning. For more interactive exercises, students can complete diagrams, timelines, practice sketch noting (visual note-taking), or graphic organizers.
One important thing to keep in mind when incorporating dual coding is that process multiple cues simultaneously can be overwhelming for students if not done appropriately. Be careful not to add extra information where it may be unnecessary or even unhelpful.
So a diagram that depicts fractions using pie slices might be helpful to add to a fractions worksheet but confusing or distracting at times table worksheet. Visuals should always support verbal material and vice versa. Simplified depictions and descriptions are the most effective. Anything overly detailed or irrelevant is distracting to students.
One recent study assessed cognitive overload in college students interacting with multimedia materials. The researchers found that segmenting and distinguishing relevant and irrelevant information promotes better learning strategies and helps students process material better.
Repetition and retrieval are particularly valuable when implementing dual coding. Using repetition of dual coding activities can help information stick and retrieval resurfaces learned material to ensure students have not forgotten it.
LaShaundra Cox, a biology teacher at Douglass High, has also implemented dual coding in her classroom. Like fellow teacher Mueller, she found the technique helpful and observed positive effects in her students. Cox is a big believer in letting her students work through problems on their own, without “babying” them, finding that they learn better when they struggle productively. “it’s better when they have to produce the visual rather than using the visual that’s already made.”
Take care that students are up to that type of independent work, especially when incorporating new learning strategies like dual coding into the classroom. As Dr. Sumeracki suggests, in some cases, providing students with simple diagrams may be necessary. Especially “if they’re not there yet, if they just stare at a blank piece of paper.”
Cox added, “dual coding works if you use the strategy the right way and you use it intentionally.”