As part of a project I am collaborating on, I recently learned about dual coding theory which was introduced by Allan Paivio in the 1970s. In short, dual coding is a cognitive psychology theory that argues that the use of visuals and words can aid the explanation of new content (to expand on learned material) and improve memory. This theory is often used in education to support students’ learning experience through the use of diagrams, timelines, graphic organizers and infographics to provide structure in the delivery of the material.
While the focus of the dual coding theory was initially on remembering information, the theory can help information design in three ways:
- provide information designers guidance about how to code information in ways that will support cognitive processes, and thus increase comprehension.
- explain why and when certain information design decisions will be ineffective.
- shed light on why, how and when information design does facilitate understanding and improve communication.
The following are six questions and four dimensions that information designers have to address at a daily basis. Learning about dual coding can provide answers to some of these questions and help understand common design problems.
Processing information. Based on dual coding theory, we mostly process information through two different channels: one channel processes visual information/stimuli and another processes verbal/textual information/stimuli. This combination of a visual code with a verbal code to learn something new is effective because it provides meaning in two complementary ways. When we learn something through two codes, we create and store two separate frames of the incoming information in our working memory, generating a more complete understanding:
- For example: If we learn the meaning of house through two codes, we generate a frame for the house word and a frame for the visual of a house; when needed, we can retrieve one frame or the other frame.
Coding a concept in two different ways (visual and verbal) increases the audience’s chance of understanding and remembering its meaning compared to only explaining a concept using one type of code.
Level of familiarity with content. Dual coding argues that the use of visuals and text helps expand understanding on learned materials. This implies that deep understanding using visuals and text is most likely to occur when the audience already has an initial set of stored frames about the content at hand; that is, the audience is not completely unfamiliar with it. If you are working with content that is completely new to an intended audience, the information design approach should be different, as dual coding theory may not work so effectively.
- For example: If you are working on a project for a novice audience, it may be more effective to design a solution with a greater amount of textual explanation than visuals rather than designing a highly visual output with minimal text, as the audience would not have stored frames for that topic. Another factor to consider is how the textual explanation is presented, as this would also impact the audience’s understanding.
Anchoring meaning of visuals: The use of words to anchor the meaning of visuals (e.g. icons, symbols) is a core information design principle which is frequently forgotten. Visual communication requires careful thought and work to find the most relevant and adequate pair of visuals and words. While attention is mostly placed on visual attributes (graphic design, visual composition, etc.), content (text/explanations) is also overlooked. Clearly articulating a concept, finding the right word, or writing a well-structured question is as important as creating the right visual or using the right color. Both poor phrasing and unclear visuals can lead to confusion or misleading information.
Creating/Using the right visual. Not all visuals will work to illustrate a concept. Before testing a design with the intended audience, it can be hard to determine whether a visual may be enhancing or hindering understanding. These are three points to consider:
- The visual should be relevant. That is, the visual should not be too detached from the meaning of the word or of its physical representation so associations between a word and a visual are direct and easy to see; otherwise, it requires too much cognitive energy to be processed and the message may not be understood, resulting in an unsuccessful text-visual marriage.
- The visual should be simple. Visuals should not be intricate or decorative; adding too much detail can hide or distract from important points. The goal should be to add only details to enhance meaning or help highlight important parts. Identifying relevant from irrelevant information and details is key to achieve this balance, and one of information designers’ essential skills.
- The visual should be familiar to the audience. As R.S. Wurman pointed out, to help explain a complex or unfamiliar topic, use a visual that is familiar to the audience. This helps narrow the understanding gap because the audience will be able to relate the incoming information with stored frames in their long-term memory, making the most of dual coding.
The more we can gain familiarity with scientific explanations, and key cognitive and psychological theories that reveal why we do what we do in the way we do it, the more we can understand how information design can support people, their needs and their interactions. This understanding will help information designers make more confident design decisions, improving the overall credibility and rigour of the field.
Miller, P. (2011) The Processing of Pictures and Written Words: A Perceptual and Conceptual Perspective. Psychology. Vol.2, No.7, 713-720