Designing effective multimedia lessons for your class

Most of us, at one time or another, have had the experience of sitting through a lecture in which we felt totally overwhelmed. This is going too fast! What was that term she used? What am I even supposed to be getting out of this? It’s pretty likely that you left that lecture with some scattered notes, many questions, and a whole lot of confusion. The speaker may have felt that her presentation was simple, straightforward, and clear while having no idea that you (and others) felt lost or confused.

As a teacher, I worry a lot about whether (or, more honestly: how often) my students have this experience in my classes. But as a researcher who studies effective multimedia instruction, there are many instructional strategies and cognitive principles that guide the decisions I make when planning my courses and my class time. As we near the start of a new academic year, this is an excellent time to share some of those guidelines and how I utilize them to try to avoid overwhelming my students, both in my live lectures and my pre-recorded video materials.

A quick note: The term “multimedia learning” is sometimes used interchangeably with the idea of “video learning”, but the concept boils down to a much simpler notion of “learning from both words and pictures”. This definition includes things like learning from video, but it also applies to an instructor lecturing with PowerPoint slides and reading a text passage with a relevant diagram. The study of multimedia learning is ultimately asking: What is the best way to design a learning experience that involves both words and pictures?

Using cognitive load as a guiding principle

As a cognitive psychologist, I am prone to thinking about learning as an information-processing problem: how do we take all of the information coming at us and decide how to make sense of it? My view has been heavily influenced by Rich Mayer’s (2005) Cognitive Theory of Multimedia Learning, which frames learning as a process of selecting, organizing, and integrating new information with what we already know. This theory also frames the goal of teaching as effectively managing the cognitive processing necessary to do that selecting, organizing, and integrating in the context of multiple sensory channels (verbal, visual), each with limited capacities.

*Mayer’s (2005) Cognitive Theory of Multimedia Learning.*

At the center of this theory is the idea of cognitive load; the balance between task demands and learner’s capacity. Individuals have unique cognitive capacities which may be more or less taxed by a given lesson. The feeling of overwhelm, for example, can occur when the processing demands of a lesson exceed the capacity of the learner, just as boredom might occur if the learner’s capacity is underutilized. The design of the lesson, the prior knowledge of the learner, and the inherent complexity of the material are all factors that will influence how much load will be placed on the learner’s cognitive resources.

Perhaps the key insight behind cognitive load theory, however, is that not all load is equal. Rather than trying to reduce cognitive load at all costs, effective teaching should aim to manage load in such a way that we prioritize sense-making over processing demands that are unrelated to our instructional goals. Decades of research in multimedia instruction have yielded principles of effective instructional design (see Mayer, 2021 for a review) that can be grouped according to 3 broad goals: reducing extraneous processing, managing essential processing, and fostering generative processing.

*Examples of instructional scenarios leading to cognitive overload or underutilization (from Mayer, 2021).*

Extraneous processing is unrelated to the goals of the lesson, and it can be reduced by making sure that your lesson avoids extraneous material, highlights key ideas, and places corresponding information close together in space and time. Essential processing is necessary for building accurate mental representations, and it can be managed by providing pre-training on key terms, making good use of both words and pictures, and breaking the lesson into shorter, learner-controlled segments. Generative processing is necessary to make sense of the material, and it can be fostered via techniques that encourage motivation to learn, including gesture, conversational language, dynamic images, and appealing voices. Generative processing can also be fostered by incorporating generative learning activities. Such activities encourage learners to generate responses that help them make connections between ideas.

Incorporating generative activities

If I have learned anything from teaching college students (and from once being a college student myself), it is that students don’t know what they don’t know; it can be hard to engage in generative processes without some guidance about what to generate! This is why well-placed activities can make a big difference in what students get out of a lesson. A generative activity can highlight that a concept is important, demonstrate the level of complexity or difficulty they should expect on later assessments, and provide guidance about the types of connections that are possible. I tend to use 3 generative techniques in my lessons:

Adjunct questions. These are questions inserted into a lesson to help students check their learning as they go. They might appear at the beginning, middle, or end of a lesson, and they could be multiple-choice or short answer, but ideally, the learner should submit an answer and see feedback before moving on.

*An example of an adjunct question in a video lecture about memory.*

Self-explanation prompts. These prompts ask students to explain a concept (or a problem, or a solution, etc.) in their own words. Self-explanation prompts can be quite open-ended (“Explain the main argument of this passage in your own words”) or they can be targeted at specific concepts (“Explain what it means to say that cognitive psychology is an ’indirect science’”).
Peer discussion. When possible, prompting students to discuss their reasoning with peers is an excellent way to deepen understanding, as they are exposed to ideas they may not have generated themselves. (I recommend Tullis & Goldstone, 2020 for an excellent review of Peer Instruction as a specific instructional technique.)

Incorporating generative activities in my lessons has the bonus effect of helping me achieve all three cognitive load goals at once. Choosing appropriate questions helps me identify what concepts I view as most important, communicates that importance to students, and motivates me to remove or deemphasize less important material (reduce extraneous processing). Pausing the lesson to give time for reflection and discussion also prevents me from running through the lecture too fast and helps students pace themselves through the material (manage essential processing). And of course, requiring students to respond to these prompts helps them make sense of the material while giving them practice with the kinds of questions they will see on later assignments (foster generative processing).

Consider the context of your course

A final recommendation for instructors is to consider how multimedia content and generative activities fit into the broader context of your course. In-person lectures offer different affordances than remote or pre-recorded content, but effective multimedia instruction does not require fancy graphics, editing, or technologies. Instead, consider how you could encourage students to engage in a brief generative activity for each lesson and how that activity can be used to manage the cognitive demands of the material. Doing so might help them avoid those feelings of overwhelm in more ways than one!