Doug Vogel’s 1986 study demonstrated a clear and significant effect on persuasion when a presentation is delivered along with supporting visuals. What is not clear from Vogel’s work is exactly how the improvement in persuasion happens. Persuasion is a complicated process involving attention… comprehension… yielding/agreement… and retention …. culminating in action. Vogel studied 17 modifiers of these components of persuasion trying to understand what was going on, but in the end his results were inconclusive and even contradictory.

Professor Richard Mayer has approached the challenge of understanding the use of visuals from a different perspective. Mayer has focused on the effect of visuals on learning. Just as Vogel developed a well researched theory of persuasion, Mayer has done extensive research on learning and developed a cognitive theory of multimedia learning. All of the research he presents in his excellent book “Multimedia Learning” is designed to test the assumptions of this theory.

Why should a Presentation Professional care about a cognitive theory of multimedia learning? Because the design of visual support material should be based on what is known about how the mind works… how information is processed and how learning occurs. Effective presentation design cannot be based on intuition, heresay or opinion. If we were to overlay Mayer’s learning theory over Vogel’s persuasion process, it would clearly overlap with the components of comprehension and retention. I believe there is also an overlap, although a little less clear, with the component of yielding/agreement. Mayer’s work is meticulously researched and referenced. While I won’t present all of his supportive references, they are available in his book for those who are interested.

Mayer’s cognitive theory of multimedia learning is based on three core assumptions:

1. Dual Channel Assumption: Humans posses separate information processing channels for visually represented material and auditorily represented material.
Information processing occurs in three general stages. Information enters our information processing system via either the visual or auditory processing channel. This is the input stage. The information is then processed separately but concurrently in working memory. Working memory can be thought of as RAM, where relevant sounds and pictures are selected and organized. Eventually the information from both channels are integrated and connected to other information already held in long term memory.

2. Limited Capacity Assumption: Humans are limited in the amount of information that can be processed in each channel at one time.
People who are listening to any presentation can only hold a few images and a few sounds in working memory at one time. This has been researched extensively in the field of psychology and is often referred to as cognitive load theory. Although there is some individual variability, memory span tests have shown that average memory span is pretty small, from 5 to 7 “chunks” of information. Because of our severely limited cognitive processing capability, we are always making decisions about the allocation of our processing resources.

3. Active Processing Assumption: Humans actively engage in cognitive processing to construct coherent mental representations of their experiences.
We are not like tape recorders. We don’t passively collect information. We are constantly selecting, organizing and integrating information with past knowledge. Active learning occurs when we apply cognitive processes to the incoming material. The result of this processing is the creation of a mental model of the information presented. The three processes that are essential for active learning are: selecting relevant material, organizing the selected material and then integrating that material into existing knowledge structures. These processes take place within our fairly limited working memory.

From these three assumptions, Mayer extrapolates a cognitive theory of multimedia learning. Remember that Mayer defines multimedia as any environment where material is presented in more than one format. Any presentation that uses visual support qualifies under this definition. Mayer’s theory states that in multimedia environments, learners must engage in five cognitive processes:
1) selecting relevant words for processing in verbal working memory
2) selecting relevant images for processing in visual working memory
3) organizing selected words into a verbal mental model
4) organizing selected images into a visual mental model
5) Integrating verbal and visual models and connecting them to prior knowledge

Discussion:
Why should a Presentation Professional care about assumptions and theories of learning?
1) If people do process information through separate but concurrent processes, then a presentation designer must be highly intentional about what and how information is presented to each channel.
2) If our cognitive processing capability is limited, then a presentation designer must be very careful not to overload either channel.
3) If our audiences are actively trying to select and organize information into models in working memory, then we need to design presentations that help our audiences do this. As Mayer suggests, the presented material should have a coherent structure and the message should provide guidance to the learner for how to build a mental model of the information.

Developing a presentation should involve much more than designing a nice template. Presentations must be constructed in a way that takes into consideration the way our minds work, and the way we learn.