This is the second part of my summary of Nine Ways to Reduce Cognitive Load in Multimedia Learning, by Richard E. Mayer and Roxana Moreno, originally published in ATD’s Science of Learning blog. 

Part 1 (here) deals with how we process information through two channels (one for words, one for images), and how overload can occur in one channel or in both.

Overload from extraneous information

(Spoiler alert: “Nice to know” doesn’t mean “good to include.”)

Mayer and Moreno point out that “interesting but extraneous material” takes up cognitive capacity. The learner has to pay some attention—for instance, it’s hard to not listen to background music. Effort goes into deciding whether anything deserves further attention. The more this happens, the less capacity remains for learning what actually does matter.

You probably can guess what the researchers recommend: weeding. Remove the extraneous. What’s the bare minimum that people need to know in order to accomplish the skill or apply the knowledge? Force everything else to justify its inclusion.

In an animated sales-call lesson, for example, I don’t need to see the customer driving in. I don’t need an animated phone, virtual pens, and virtual paper clips. I do need a customer statement to respond to. I need time to analyze it. I need clear examples of responses and how effective they are in a situation like the one I’m seeing.

To me, the weeding of nonessential material is the difference between the rich but irrelevant detail of a war story and the crisp relevance of a pertinent example. Our interview candidate probably doesn’t need to know that there’s a library two blocks before she gets to Midcounty Highway; she does need to know when she gets there, the two right lanes are right-turn-only.

Granted, sometimes you can’t edit details out. Suppose you’re explaining how to operate packaging machinery in a pharmaceutical plant. Your learner will confront lots of equipment and lots of steps, along with potentially overwhelming detail in the video close-ups.

When weeding is not an option, Mayer and Moreno recommend is signaling—providing cues to the learner about how to organize the material. So, the lesson might start by breaking packaging into four stages: product into plastic blisters, blisters into cardboard wallets, wallets into carton packs, cartons into cases. In subsequent lessons, arrows or similar highlighting emphasize key components of each stage.

Overload from poor presentation

Sometimes overload results from the confusing presentation of essential information. Imagine an animation in one part of a screen and related text in another. The learner has to shift focus between the two areas, as well as figure out which parts are related to which.

Mayer and Moreno recommend closer alignment of words and pictures. Placing text inside a graphic, rather than alongside as a caption, aligns the explanation more closely with the visual for what’s being explained.

In a related situation, information arrives as animation, onscreen text, and audio narration. The simultaneous presentation of text and narration, which the researchers call redundant presentation, requires the learner to work at reconciling the two verbal forms while also dealing with the visual form. It’s as if our interview candidate were watching an animation of the route to follow and reading directional text while the person next to her recited those directions.

Mayer and Moreno cite studies with a significant shift as a result of reducing redundancy, such as dropping onscreen text and using only narration. An interesting twist they add is that if there’s no animation, students learn better from concurrent narration and on-screen text than from narration alone. The interpretation is that the on-screen text by itself doesn’t overload the visual channel the way it would with the animation there as well.

Overload from “Hold that thought!”

The final type of cognitive overload involves both essential processing and “representational holding.” Mayer and Moreno explain that as having to retain information in working memory. For example, if you read about the thermoforming process for drug packaging, and then watch a video showing the process, you have to keep elements of that text in memory during the video, which reduces your ability to select, organize, and integrate.

One way to avoid this overload is to synchronize—interweave text or audio with the video. Words about the sealing step should arrive as the visual does; a description of the check-weigher should come while the learner sees that device in action.

Researchers cite robust evidence that “students understand a multimedia presentation better when animation and narration are presented simultaneously rather than successively.” Meanwhile, Mayer and Moreno point out that if the non-synched elements are brief—a few seconds of narration followed by a few seconds of animation—there’s less overload, mostly likely because the learner has less representational holding to do: fewer things to keep in mind from the verbal information.

But what if you can’t synchronize? Then, the recommendation is individualization, or ensuring that you have learners skilled at holding things in memory. If for your work you’re able to match “high-quality multimedia design with high-spatial learners,” you’re all set. Personally, I’m rarely able to manage that.

Final thoughts

I started by comparing the multimedia learner to someone who has to drive through a strange city to make an interview. Mayer and Moreno highlight ways that your design decisions can make that trip far more difficult than necessary. Pick up some learning principles and lessons from this research—and take off a little cognitive load.