Nine Ways to Reduce Cognitive Load in Multimedia Learning

by Richard E. Mayer and Roxana Moreno

SUMMARY

INTRODUCTION

The articles intended purpose is to provide instructional designers with the needed insight, knowledge, and skills to design and create meaningful instruction that does not result in students experiencing cognitive overload during learning. The article begins by exploring the theory of multimedia learning which explains that humans possess separate systems for processing pictorial and verbal material – called the dual-channel assumption. When either or both of these channels become overloaded with too much data (stimuli) the student experiences cognitive overload which in turn prevents meaningful learning. The authors begin the article by defining multimedia learning as “learning from words and pictures” and multimedia instruction as “words and pictures that are intended to foster learning.” Meaningful learning results in the student achieving a “deep understanding of the material, which includes attending to important aspects of the presented material, mentally organizing it into a coherent cognitive structure, and integrating it with relevant existing knowledge.”

The authors provide a description of the dual channel assumption which explains that the dual channel model includes an auditory/verbal channel for processing auditory input and verbal representations and a visual/pictorial channel for processing visual input and pictorial representations. Key elements of this model are the Dual Channel Assumption (the brain processes data in two separate channels), Limited Capacity Assumption (each channel has a limited capacity for collecting and processing/storing data), and the Active Processing Assumption (the brain must actively select, organize, and integrate the learning). Cognitive overload can and does occur when too much data is taken in, or it is taken in too fast, for the brain to process it. The following illustration shows how new data is processed and shared.

THE CASE OF COGNITIVE OVERLOAD

Cognitive overload occurs when the processing demands demanded by a learning task exceed the processing capacity of the cognitive system. The authors describe three kinds of cognitive demands: essential processing, incidental processing, and representational holding. Essential processing refers to the cognitive processes that are required (essential) to make sense of the material p[resented for learning. Incidental processing refers to the cognitive processes that are not required or essential for making sense of the presented material but are part of the design of the learning – usually more cosmetic than value-added. The last, representational holding, refers to cognitive processes needed for developing and holding a mental representation of what is being learned in working memory. The tezt discusses 9 methods used to prevent cognitive overloading:

Off-loading                                    Segmenting                             Pretraining

Weeding                                        Signaling                                 Aligning words and pictures

Redundancy Elimination                  Synchronizing                         Individualizing

The following define ways in which overload occurs and example of strategies to prent these situations.

Type 1 Overload: Off-Loading – occurs when one channel is overloaded with too many essential processing demands. This often occurs when one channel is forced to deal with input from two different sources at the same time creating a condition referred to as split-attention effect. In the figure above, this is represented by the two arrows from one channel (Multimedia Presentation - Words) providing output to two channels (Sensory Memory - Ears and Eyes) simultaneously. A common cause for this condition is the eyes receiving data from two different sources – the written word and pictures/graphics/drawings, etc. The best solution is to off-load excess data to a different track; e.g., convert the written text to narration.

Type 2 Overload: Segmenting and Pretraining - occurs when both channels are overloaded with essential processing demands. This is typically the result when both channels are overloaded with essential information that is content rich and delivered at a pace too fast for the student to properly receive and digest it. The two best solutions for this condition are to use segmenting and pretraining. To segment, the content is broken down into smaller bite sized portions – a process referred to as chunking - which gives the student more time and a better structure for receive and digest the information. In pretraining, the cognitive load is transferred to an alternate means or location and provided as pretraining. (We use pretraining a lot for Navy training. We do this by providing some of the key concepts, principles and processes online using Navy e-Learning and the Navy Knowledge Online NeL NKO) portal. Putting this information online and making the training a required prerequisite to staring the actual training course lessens the cognitive load in the class.)

Type 3 Overload: Weeding and Signaling – This occurs when the system (one or both channels) is overloaded by a combination of essential processing being combined with incidental processing demands due to extraneous material. Typically, this extraneous information is interesting, but of limited value. The two solutions for this case are weeding and Signaling. For weeding, examine the content and eliminate interesting material that is not value-added. Signaling requires you to organize and present the material in a way so the student can recognize essential content from content that is “nice to know.” I often do this by adding links or pop-ups for “nice to know information, this gets it off the same page as essential ionformation. If on the same page, I might put it in a side bar or in a text box.

Type 4 Overload: Aligning and Eliminating Redundancy. This occurs when the system (one or both channels) is overloaded by both essential and incidental processing demands resulting from the manner in which the essential material is presented – usually in a confusing way. I often see this occurring when the text is on one part of a page and a drawing or diagram is not immediately adjacent, or maybe on a totally separate page. The best solution for this case is to align the text and graphical representations – better yet, integrate the two. The other case for this occurrence is when the material is unnecessarily presented too often and/or in a confusing manner to the point that the material becomes redundant. The solution to this scenario is to eliminate unnecessary redundancy (the authors agree that this is similar to case for weeding above.)

Type 5 Overload: Synchronizing and Individualizing – used when the system is overloaded by the need to hold information in working memory while new or related information is presented in direct, unbroken succession. The example in the text illustrates an example where the material is first presented in one format (narration) and then immediately presented in a second format (animation) before allowing the first presentation to be absorbed. The first solution is to use synchronizing whereby the successive presentations are synchronized or integrated. For this instance, UCSB studies indicate that students understand a multimedia presentation better when animation and narration are presented simultaneously rather than successively. Individualizing can also be used when it is known that the target student population are high spatial learners who have the ability to hold and manipulate mental images with a minimal amount of cognitive energy. (Individualizing will not work for low spatial learners.)

DISCUSSION

This article hits very close to home for me. One of my jobs is to provide an ISD review for all products under development. The purpose for the ISD review is to ensure objectives are met and that solid instructional design principles are/were used in designing and developing the material. Based on experience, I can relate to almost every example given in this article; some of which I am guilty of. It is going to be nice to have an academic writing and the UCSB studies to back up many of the recommendations that I have been making.

For example, this week I reviewed a 130 slide PowerPoint presentation that details how a major system on a ship operates. The presentation is being converted for use as a student handbook (Trainee Guide) to be used as part of on-the-job training presented by subject matter experts during ship visits. One of my first observations to the developer was that he was being redundant to the point that it was confusing. I kept asking myself, why is he presenting this material again? (The developer seemed to think the redundancy was needed to drive the material home. He was overdoing it.) As stated in the reading, effective instructional design depends on the instructional designer (and the content developer) having sensitivity to the existence of cognitive load which, in turn, depends on his/her having an understanding of how the human mind works.

Lastly, this article applies to any multimedia presentation no matter the media used to presnt the material to the student. In particular, I have seen PowerPoint presentations that need lots of help. Especially when the developer thinks that if a little information is good a whole bunch of information must be proportionally better. Try as hard as I can, I am not always successful in convincing developers that sometimes less is more when it comes to providing effective training. And, I am sure most of us are familiar with the term, "Death by PowerPoint."