Multimedia Learning Principles
The effective design and use of multimedia materials requires an understanding of some basic cognitive psychology principles.
Our understanding of how to create pedagogically effective course videos relies heavily on our understanding of cognitive psychology. This makes sense - how we process pictures and words and store information in short- and long-term memory provides guidance on how to effectively craft educational "multimedia messages": pictures and words seen by the eyes and spoken narration heard by the ears.
In this article we'll discuss the core cognitive components of multimedia learning: how we process pictures and words, active learning, and how different kinds of information affect our limited cognitive capacity. Once we have an understanding of how our brains process pictures and words designed to teach, we can leverage that information to generate best practices for creating effective course videos.
The Short Version
In order to understand how we learn via multimedia, we have to begin with three assumptions about how we process information. First, we perceive multimedia messages almost exclusively through two channels: a visual channel and an auditory channel (the dual channel assumption). Secondly, we can only perceive so much information at once (the limited capacity assumption). Lastly, learning doesn't occur passively - we need to do work in order to actually learn (the active processing assumption).
But what does it mean to "actively process" information? Well, first the learner must select the most important pieces of information. (We have a limited capacity, after all.) Next, they have to organize them into some sort of model that makes sense to them. Finally, they have to integrate that model with what they already know (prior knowledge).
Lastly, during learning there are three main sources of cognitive effort: the inherent complexity of the material, stuff that's not relevant to the learning goals, and the work involved with the active processing task discussed above.
Understanding the details of this cognitive theory of multimedia learning will help to provide a framework for how to leverage what we know about human perception and cognition to design effective multimedia.
Information Processing
In his book Multimedia Learning, Richard Mayer wishes to develop what he calls a cognitive theory of multimedia learning. In order to do so, he relies on three main assumptions about how we process information when the brain perceives a multimedia message:
- The dual channel assumption
- The limited capacity assumption
- The active processing assumption
The Dual Channel Assumption
We have two separate intakes or "channels" for processing a multimedia message: the visual channel and the auditory channel.
The visual channel processes images seen through the eyes (both pictures as well as printed words) while the auditory channel processes spoken words. So, in the example of our multimedia message, the visual content of the slide is processed by the visual channel and the words spoken by the presenter are processed by the auditory channel.
The Limited Capacity Assumption
We have a limit on how much information we can process at any given moment.
Research suggests that most people can maintain maybe 5-7 "chunks" of information in working memory at any given time (Mayer 67). However, both the visual and auditory channels have their own separate capacities, and while either can be overwhelmed by excessive load, using pictures and words strategically can essentially "split the load," allowing more to be processed and retained.
The Active Processing Assumption
In order for learning to occur, the learner must expend cognitive effort.
This assumption embodies the constructivist model of learning, in contradistinction to the "knowledge transmission" model. We don't learn by passively absorbing information, but rather we have to engage in cognitive activity to process and integrate the multimedia message.
Active Processing
The assumptions on how we process information provide some clues on how to construct an effective multimedia message. For example, the fact we have two channels for information processing suggests that if we split a multimedia message between them, we can teach more effectively. The limited capacity assumption suggests that we need to be careful about how much information to present at any given time. The active processing assumption encourages us to motivate our students so that they're willing to do the work necessary to learn.
But what does "active processing" mean? As suggested earlier, learners aren't "empty vessels" waiting to be filled up with information by an expert. Let's explore, then, the cognitive processes that take place during active processing. At a high, level, there are three main steps:
- Selecting relevant material from the multimedia message
- Organizing the selected material into coherent representations
- Integrating representations with existing knowledge
Selecting Relevant Material
The learner must first identify the most important and relevant pieces of information from the multimedia message.
As mentioned above, the brain has a limited capacity to process information at any given moment, so learners have to figure out the most important bits. The ability to identify these pieces is greatly aided by effective instructional and multimedia design, in particular by drawing attention to salient words and images (through, say, animations or arrows). Once selected, the material moves to the learner's working memory (the cognitive system where information can be manipulated).
Organizing Selected Material
Learners must then represent those selected materials in a verbal or pictorial model that makes sense to them.
Once in working memory, the learner establishes structural relationships between the selected materials and builds a mental model of some sort. Given that this step takes slightly more conscious effort on the part of the learner, this step is especially boosted by the learner's motivation.
Integrating Representations
Lastly, learners must integrate the representations of selected material with what they already know.
When organizing selected materials, learners are establishing relationships between the new materials in working memory, but during integration, the learner essentially brings prior knowledge out of long-term memory and has to fit in the new material with the old. Given that all knowledge is built on a foundation of prior knowledge, this is a crucial step. As Mayer says in Multimedia Learning, "Prior knowledge is the single most important individual difference dimension in instructional design" (193).
Cognitive Load
The limited capacity assumption suggests that both the visual and auditory channels can be oversaturated by excessive cognitive load. But what is "cognitive load?"
Earlier, we discussed that we have a limit on the amount of information we can process at any given moment. Cognitive load theory separates instructional information into three different categories, and in turn provides instructions on what instructors should do about each type. In short, instructors should:
- Manage intrinsic load
- Optimize germane load
- Minimize extraneous load
Each type of load is the result of the arrangement and relationship of the components of the multimedia message and - for the most part - is the product of instructional design. Accordingly, understanding the learning impact of each type of cognitive load is crucial to creating effective course videos.
Manage Intrinsic Load
Intrinsic load is cognitive effort required to represent the multimedia message in working memory.
This is really about the complexity of the material. Earlier we discussed that the first stage of active learning involves selecting the most salient pieces of information from the multimedia message - this part of active learning is most directly affected by the intrinsic load of the message.
Instructors should aim to manage intrinsic load. Instructors can't fully control it - after all, "complexity" is dependent on a variety of variables that are specific to each learner. That said, the best practice of "chunking" - breaking knowledge and skills into its component parts - is really about managing intrinsic load.
Optimize Germane Load
Germane load is cognitive effort required to process and integrate the multimedia message.
Germane (or "generative") load is somewhat dependent on how motivated the learner is to attend and learn. With respect to active learning, generative load is really about the latter two stages: organizing selected materials into coherent representations and integrating those representations with prior knowledge.
In many ways, germane load is the good stuff: effort devoted to learning.
Minimize Extraneous Load
Extraneous load is cognitive effort that doesn't support learning outcomes.
In a multimedia message, there are often words and pictures that distract from the learning outcomes. Ideally, such details should be removed. Examples of extraneous load could be decorative clipart, an unrelated anecdote, eye-catching animations, or background music.
Interestingly enough, extraneous materials are sometimes better retained than the essential material, which is why they're sometimes referred to as seductive details: "interesting but irrelevant material that is added to a passage in order to spice it up" (Mayer 93). This may contradict common sense that arousal promotes engagement, which in turn helps students learn, but the research is clear that these details just compete for our limited cognitive resources and take away from meaningful, active learning.
The Big Picture
Understanding how we process information is crucial for developing effective course videos; indeed, for developing effective multimedia presentations of any kind. Information processing assumptions, for example, suggest that we have to use pictures and words strategically, even sparingly. The details of how active learning works suggest that we need to help learners make sense of the material and create conceptual scaffolds. Lastly, cognitive load theory endorses chunking and a strong focus on learning objectives.
Overall, the cognitive psychology foundation underpinning multimedia learning theory strongly - if implicitly - advocates for a constructivist approach to teaching and learning. Instead of dumping knowledge into students, instructors must instead tactically encourage students to engage in active learning through the design of their materials.
Check out our presentation design guide, which leverages these and other psychological principles to offer practical tips on how to design visual aids.