Dual Coding Theory and Teaching

by Susan Codone

Allan Paivio initially proposed Dual Coding Theory in 1971 to explain his view of how we remember pictures and words.  The Stanford Encyclopedia of Philosophy describes Dual Coding Theory as one of the most influential theories of cognition in the 20th century. Paivio states that his theory of cognition has roots in the practical use of imagery as a memory aid going back over 2500 years (Dual Coding Theory and Education, 2006).  In fact, he says that memory is crucial to Dual Coding Theory because it is the basis of all knowledge and thought.

Paivio argues that there are two ways a person can elaborate on material.  One form of elaboration uses verbal associations; the other form creates a visual image to represent a picture or word.  Paivio says that pictures result in better memory and the potential of imagery is a more reliable predictor of learning than words.  Dual Coding Theory proposes two independent memory codes which together increase the chance of successful information retrieval.


Teaching with Dual Coding Theory
Richard Mayer, who has proposed the Cognitive Theory of Multimedia Learning, borrows the concept from Paivio that the learner possesses both a visual information processing system and a verbal information processing system (Richard Mayer and Roxana Moreno, A Cognitive Theory of Multimedia Learning: Implications for Design Principles, 2005).  Both he and Paivio apply their theories in teaching by saying that whenever you teach a concept with words, pair it with an associating picture in order for your students to more easily transfer it from working memory to long-term memory.  For example, the two PowerPoint slides below illustrate this principle; the first is text only, while the second uses the most important text along with a relevant picture of what is being taught.

We all know that text-only slides are not as effective as a slide with text and a relevant picture.  In teaching, though, our use of pictures and text goes beyond teaching efficiency; by offering students both mediums, we open two channels into their working memories, thus laying down more solid neural pathways and making later retrieval much easier.  We make it easier for them both to learn and to recall information later when we use two channels of presentation.

Take a look at this screen grab from a medical e-learning course from Interact Medical.  This particular screen displays text on the left with an explanatory picture, including labels, on the right.  Now, medical education is very dependent on pictures, but this slide is actually more efficient than most; the text on the left "primes" the user to understand the picture on the right, and the picture confirms the message of the text. In the event the student looks at the picture first, the opposite effect occurs -- one pathway is laid down and the student next associates the text with the picture.  Both the visual and verbal information processing systems are invoked in the learner and the message of the text and the image both go together into working memory, linked by association as they eventually move into long-term memory.  The learner can then more easily retrieve the message by recalling the text and the picture, because both are linked by association in long-term memory.

Paivio says that images are more effective in both encoding into memory and retrieving from memory because an image provides a "'second kind of memory code independent of verbal code".  Mayer, in his research on multimedia and cognition, builds on Paivio's work by offering several principles of multimedia learning, the first of which is that it is better to present an explanation in words and pictures than solely in words.  Mayer says there is a multimedia effect consistent with a cognitive theory of multimedia learning because students shown multimedia explanations are able to build two different mental representations -- a verbal and visual model -- and build connections between them.

If you don't know what a kangaroo is, which picture is better?

Dual Coding Theory has great implications for teaching and learning.  Essentially, we do our students a favor when we offer multiple presentation modes to them while teaching -- we make it easier for them to acquire the  information, make associations, store it in working memory, transfer it to long-term memory, and then recall it later.  As professors, we can be better informed by the use of this theory, and our students will benefit.

Relevance & Undergraduate Teaching

This semester I have developed a new understanding of the importance of relevance to undergraduate students, particularly freshmen.

To teach engineering ethics to freshmen students, we often turn to engineering disasters. These case studies often involve ethical problems that contributed to the disaster, such as the epic struggles between engineers and NASA managers over the launch of the Space Shuttle Challenger. Those ethical problems, added to the spectacular stories of the disasters, usually make a compelling lesson.

Usually!

A few days ago I prepared a lesson using the Teton Dam collapse as the primary case study. I prepared the case study and even found a great website with moment-by-moment pictures of the leak that turned into the collapse of the dam. I even found a picture that showed a tiny speck coming down from the top of the dam toward the leak – it was a bulldozer sent down in a futile effort to stop the leak. Moments later the leak opened into a huge hole, swallowing the bulldozer. I felt certain my students would be fascinated.





After I presented the case and the pictures, I expected questions (sometimes I find myself expecting applause for particularly great lessons) but I received mostly blank stares. One student from the back ventured, “Katrina?” With that one word, I suddenly understood. The Teton Dam collapsed in 1972. There is no good video of the event on YouTube. The collapse only killed 11 people and the flooding was not extensive. In their minds, not only was this disaster quite old, it was out of their personal experience range and was therefore not relevant. Katrina, on the other hand, they knew about. It was relevant because they witnessed it in 2005, when they were 13, and they felt the extent of the tragedy. It was relevant to them because it was huge in scope and garnered an international response.

These students were born in 1992. The Space Shuttle Challenger is not part of their experiential understanding. Neither is Three Mile Island, the Ford Pinto explosions, or Chernobyl. I know where I was when the Challenger exploded. The defining moment for these students is September 11. They were 9 years old and it was the first extraordinary event they witnessed that was not part of history, and now they will compare every event like this to their experience in 2001. These students understand why terrorism is now considered an emerging technology.
So the challenge is to make historical issues relevant. Just conveying the information, even with the addition of media, is not enough. Spectacular stories aren’t enough. We have to connect to their prior knowledge and experience so that they can create new experiences and new meanings.

I am learning this as I go, making mental notes to consider relevance before I deliver any lesson. I am reminding myself that just like them, I knew where I was when….it’s just that we know different events on different timetables, making relevance a factor.