Cognitive Load Theory

Introduction
Cognitive load theory (CLT) draws on research about cognition and memory to inform the design of learning activities and documents.[1] It focuses on the relationship between working memory and long-term memory in the learning process. The basic premise is that working memory is inherently limited and can be easily overloaded by unnecessary details.

Technical writers can use this theory when they are deciding how to present knowledge to a particular audience. Audiences that are new to a topic need to learn the basics first, ideally in a relatable context.[2] In addition, the amount of redundancy should be adjusted according to the audience's level of expertise.[12]

Memory and Schemas
Working memory is the arena where conscious thought and problem solving take place. On its own, working memory can only handle a few interacting elements at a time. When working memory incorporates information from long-term memory in the form of schemas, processing capacity increases. Schemas are mental constructs used to organize, interpret and manipulate information.[1][3][5]

[[File:Cog load theory1.jpeg | thumb | 200px | left | The schema for “leaf” is nested within the broader schema for “tree” [13].]

For example, if a person is asked to spell a familiar word backward, their working memory retrieves a set of schemas from long term memory. This set includes a schema for the spelling of the word, a schema for the letters that make up the word, and a schema for the abstract shapes that correspond to those letters. If the same person is presented with a sequence of 10 random numbers and asked to repeat them backward, their lack of a long-term memory schema for that sequence would impose a large cognitive load on their working memory.[1]



History
Foundational work towards CLT began in the 1950’s with the emergence of cognitive science as a field.[5] During this period, G.A. Miller published his seminal paper “The Magic Number 7”, where he proposed the concept of limited working memory.[6] In 1998, John Sweller introduced cognitive load theory in his paper “Cognitive Load during Problem Solving: Effects on Learning”.[7]

Theory
Cognitive load is broken down into three types: intrinsic, extraneous and germane. These different forms of cognitive load all draw resources working memory. For learning to take place, cognitive load should not exceed the capacity of working memory.[1][8]

Intrinsic
Intrinsic cognitive load is directly related to the complexity of the material being taught. It is not relative to individual learners but rather intrinsic to the material itself.[1]

Extraneous
Extraneous cognitive load comes from elements of instructional design with no instructional value that tax working memory. An example of extraneous cognitive load is a graph labeled with referents like A, B, and C, which refer the learner to a key. The working memory activity of matching the parts to their referent has no relation to the material at hand and imposes an extraneous cognitive load.[1]

Germane
Germane cognitive load is the type of cognitive load that contributes to learning. This occurs by encouraging schema creation and use. Connecting new material to a context relevant to the audience increases germane cognitive load.[1]

Intrinsic and extraneous cognitive load combine to place demands on working memory [15].



Practical Applications
Many insights from CLT apply to a wide variety of audiences. However, technical communicators want to gear learning materials toward their target audience. One important concept, known as the expertise-reversal effect, offers insights about texts made for beginners and those made for experts.[12]

Novice learners
The expertise-reversal effect has to do with the benefits and drawbacks of redundancy for different learners. Children and students who are new to a topic will benefit from some redundancy, because the repetition helps create schemas in long-term memory. However, once those schemas are set in long-term memory the redundancy will inhibit learning. This supports a scaffolding approach where redundancy is higher in the beginning and drops off slowly as the concepts are learned.[12]

In addition, instructional designers should introduce a topic fully before it is used to solve problems. For example, if students are asked to evaluate and compare different economic systems while they are still forming a basic definition of economics, they could experience cognitive overload. According to CLT, the conceptual introduction must come first. Once a student has transferred ideas about economic systems into long term memory they can more easily draw those concepts, or schemas, back to short term memory for problem-solving.[2]

Experienced learners
According to the expertise-reversal effect, learners with more knowledge on a topic will be hampered by redundancy. Since they already have schemas for the introductory materials, repetition will impose extraneous cognitive load.[12]

Tips to reduce demands on working memory

 * 1) Pose goal-free problems and problems with a relatable context. Context is key because learners can draw on their network of existing schemas.[8]
 * 2) Present all needed materials in one place. For example, avoid constructions like “see page 45 for part two of the project”. Include that information in the text at hand instead.
 * 3) Taper off redundancy for novices, remove it entirely for experts.[12]
 * 4) Use visual and auditory sources with appropriate redundancy for the audience.[12]

Future Considerations
Cognitive load theory continues to evolve and change. Research about how to apply CLT in different learning environments is ongoing.[10]

Calls for research
Researchers have called for more case studies illustrating CLT principles in action. The focus of this proposed research would be on documents that have been reconfigured to reduce strain on working memory and enhance learning.[4]

Embodied cognition
Embodied cognition research focuses on the role of the body in learning and is relevant to interactive learning in instructional design. Cognitive load theorists have called for updates to CLT to include new findings from embodied cognition research.[11]

Cognitive Theory of Multimedia Learning
This theory emerged from CLT and focuses on multimedia learning materials.[10]