(Note from J. Danielson: This section contains some information about Cognitive Load Theory (CLT) from the perspective of an educational designer/researcher -- my perspective. I wrote this section to accompany several workshops that I or H. Bender and I have delivered to a Veterinary Medical audience. My purpose is to explain CLT in a way that it can be applied practically by faculty. Hopefully, in so doing, I have not introduced any erroneous ideas or misconceptions that would make the psychologists who developed the theory cringe.)

Cognitive Load

As your students attempt to learn what you are teaching in a way that will be retained and useful to them in practice, their biggest limitation (and their biggest asset) is their own mind. As an instructor, you can design “cognition-friendly” presentations and activities. One useful way to think about the mind is in terms of its inherent limitations and strengths, and the cognitive load that is placed on it by various activities.

There are a growing number of sources of information regarding cognitive load and Cognitive Load Theory (CLT). The information about cognitive load theory in this document is drawn largely from vanMerrienboer and Sweller’s 2010 article in Medical Education¹ regarding the implications of Cognitive Load Theory (CLT) to medical education. (The allusion to rock climbing and examples in the Table are mine.)

The Human Cognitive System is limited

For novel information obtained through sensory memory (i.e., what you observe for the first time), the human cognitive system (working memory):

Can hold no more than 5-9 information elements at one time
Can process no more than 2-4 elements simultaneously
Can deal with information for no more than a few seconds. New information is lost within 20 seconds without rehearsal.

The Human Cognitive System is amazing

There aren’t known limitations when dealing with information retrieved from long-term memory.
Human expertise comes from knowledge organized in schemas, not from an ability to engage in reasoning with many elements of new information that have not been organized in long-term memory.
Expertise develops as learners mindfully combine simple ideas into more complex ones (resulting in schemas).
Even a highly complex schema can be dealt with as one element in working memory.

Schemas (“Chunks” of related information) result from:

Bringing elements together during problem solving* *
Incorporating new elements into already existing schemas in memory
Obtaining already schematized information from other people.

Over time schemas become automated through repeated application with desired results. This frees up working memory, because the behaviors can happen automatically without involving working memory.

Experts have many appropriate schemas for dealing with common problems. The more one knows about a problem, the fewer cognitive resources are needed to deal with that problem. Table 4 illustrates how many data elements can be chunked into a single element. In the the first row, 12 dissociated letters (on the left) are meaningfully combined to form a word (on the right) which is easily remembered on its own, and is associated with a number of related concepts. In the second row, a set of dissociated words (on the left) have been combined to form the first section of a famous document, the preamble to the Constitution of the United States. Again, the section of organized text is much easier to remember than the section of disorganized text. In the third row, a disorganized group of history findings and data abnormalities for a veterinary case (on the left), have been organized (on the right) to express a set of propositions indicative of the diagnosis in this case: starvation.

Table 4. Examples of Bringing Elements Together:

Disassociated Ideas		Brought together (chunked)
a n e e c l c y p o d i		encyclopedia
all truths to we that self-evident equal are men created they are Creator that endowed by these their be. . .		We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator. . .
Called by the Humane Society Several hunting dogs in a pen Cachectic , hyperglycemia, leukocytosis neutrophiiia, lymphopenia, monocytosis, eosinopenia		M. Starvation H. Called by Humane Society H. Several hunting dogs in a pen PE. Cachetic M. Cortisol resease M. Hepatic gluconeogenesis D. hyperglycemia Pat. Stress/steroid leukogram M. slight increased release of neutrophils from bone marrow storage pool D. neutrophilia D. leukocytosis M. down-regulated adhesion molecules on neutrophils and monocytes D. neutrophilia D. monocytosis D. leukocytosis M. possible decreased release from bone marrow D. eosinopenia

Cognitive Load -- Illustrated

When we learn, a load is placed on our cognitive system (brain), which can only handle a finite amount of new information. Cognitive Load theorists suggest that it is useful to think about that cognitive load in three ways: intrinsic, extraneous, and germane. It might help to think of cognitive load as you might think about the challenge faced by a rock climber, who must also carry a load over sometimes difficult terrain (Figure 1.)

Intrinsic Load:

In Figure 1, the rock climber faces some challenges that are an inherent and unalterable characteristics of his task, including his own weight and the angle/nature of the rock face he is ascending. His training (strength, endurance, etc.) also affect the difficulty of the task for him, and therefore, its intrinsic nature.

Extraneous Load:

The rock climber in Figure 1 is carrying very little that might be considered extraneous, or not useful/beneficial for his task. Even the hat is relevant if it keeps sweat out of his eyes and the sun off of his head. If he were carrying a backpack full of marbles, that would most likely constitute extraneous load.

Germane Load:

Germane is synonymous with relevant. In Figure 1, the climber is carrying several things that would be considered relevant to the climbing task he is attempting; these objects introduce extra, but justified weight, including climbing shoes (not shown) to help his feet grip the surface, a chalk bag to help his hands grip the surface, and a climbing harness and rope -- both to provide safety.

Managing Climbing Load for the Learner

Let us suppose that a beginning climber wished to learn how to climb the rock face shown in Figure 1. Upon attempting to climb the challenging rock face for the first time, he would likely fail. An experienced trainer could work with him to reduce the intrinsic load of the task (for him), and eliminate extraneous load. The trainer would also introduce germane load that would help the climber as he learned to master the new task. Strategies for reducing intrinsic load during initial learning might include starting out on less challenging surfaces (less steep, or having more handholds), or doing the climb in short sections, slowly building up to the full climb. Germane weight involves the necessary weight discussed earlier. Germane tasks designed by the trainer might also include some of the strategies on the right in Figure 1 -- designed to improve the learner’s strength to weight ratio through appropriate exercises and diet. Naturally, the trainer would not suggest activities that might increase extraneous load, such as superfluous gear, fat-inducing habits, or extra luggage that would slow the learner’s progress.

Managing Cognitive Load During Learning

Just as the mountain climber’s trainer seeks to reduce intrinsic load by increasing the climber’s ability, eliminate extraneous load, and introduce germane load during training, you can help manage the kinds and amounts of cognitive load that are placed on your students during learning.

Cognitive Load Theory Recommended Strategies:

Van Merrienbӧer and Sweller¹ recommend a number of research-based strategies for managing cognitive load. We have not included them all here, as there are several for which we have not encountered obvious application in medical sciences instruction. Note that several of these examples involve the expertise-reversal effect, meaning that their effectiveness decreases and then reverses as learners become more expert at the task. Therefore, fading guidance strategies (slowly removing help/guidance) is often effective. (Principles that have been shown to be influenced by the Expertise Reversal Effect are labeled with an asterisk.)

Decrease Extraneous Load (6 research-based strategies from van Merrienboer JJ, Sweller J)
1. *Worked Example principle. Give learners completed explanations to study, rather than requiring them to generate the solution.
2. Completion Principle. Provide a partial solution which must be completed by the learner.
3. *Split Attention Principle. Replace multiple sources of information divided by space/time with a single, integrated information source. – Makes mental integration unnecessary. (E.g., integrate a figure with explanatory text, rather than having text apart from the figure.)
4. *Modality principle. Replace a written explanatory text and another source of visual information (such as a diagram), with a spoken explanatory text and the visual source of information. (Note: Auditory and visual processing do not use the same resources, so you get a little “boost” in the amount of information that can be processed at once.)
5. Redundancy Principle. Replace multiple sources of information that are self-contained with only one source. (E.g., reduce unnecessary processing of redundant information. Don’t require students to attempt to figure out if the repeated information is somehow “new” or “different”.)
6. Managing Intrinsic Load
  1. Simple to complex sequence (E.g. begin with easier cases or problems, and slowly progress to more involved ones.)
  2. Low to High Fidelity (E.g., begin with problems that include only some aspects of the authentic problem (such as a paper case), followed by higher fidelity problems (such as a simulated case) followed by fully authentic problems (such as a real hospital case.)
  3. Optimize (increase) germane load
    1. Variability of Learning Tasks (Makes initial learning more difficult, but improves transfer and retention)²
    2. Self-Explanation (elaboration)

1. van Merrienboer JJ, Sweller J. Cognitive load theory in health professional education: design principles and strategies. Med Educ 2010;44:85-93.

2. Paas FG, Van Merrienboer JJ. Variability of worked examples and transfer of geometrical problem-solving skills: A cognitive-load approach. Journal of Educational Psychology 1994;86:122-133.