Cognitive load
Encyclopedia
The term cognitive load is used in cognitive psychology to illustrate the load related to the executive control of working memory
(WM). Theories contend that during complex learning activities the amount of information and interactions that must be processed simultaneously can either under-load, or overload the finite amount of working memory one possesses. All elements must be processed before meaningful learning can continue.
Instruction may be aimed at teaching learners problem solving
skills, thinking and reasoning skills (including perception, memory, language, etc.). Many would agree that people learn better when they can build on what they already understand (known as existing schemas
), but the more a person has to learn in a shorter amount of time, the more difficult it is to process that information in working memory. Consider the difference between having to study a subject in one's native language
versus trying to study a subject in a foreign language. The cognitive load is much higher in the second instance because the brain must work to translate the language while simultaneously trying to understand the new information.
Another aspect of cognitive load theory involves understanding how many discrete units of information can be retained in short-term memory
before information loss occurs. An example of this principle that seems to be commonly cited is the use of 7-digit phone numbers, based on the theory that most people can only retain seven "chunks" of information
in their short-term memory.
's theory employs aspects of information processing
theory to emphasize the inherent limitations of concurrent working memory
load on learning during instruction. It makes use of schemas
as the unit of analysis for the design of instructional materials.
of information in their short-term memory. Simon and Chase used the term "chunk" to describe how people might organize information in their short-term memory, this chunking of memory components has also been described as schema
construction.
John Sweller
developed cognitive load theory (CLT) while studying problem solving. While studying learners as they solved problems, he and his associates found that learners often use a problem solving strategy called means-ends analysis
. He suggests problem solving by means-ends analysis requires a relatively large amount of cognitive processing capacity, which may not be devoted to schema construction. Instead of problem solving, Sweller suggests Instructional designers should limit cognitive load by designing instructional materials like worked-examples, or goal-free problems.
In the 1990s, cognitive load theory was applied in several contexts and the empirical results from these studies led to the demonstration of several learning effects: the completion-problem effect; modality effect
; split-attention effect; the worked-example effect
and the expertise reversal effect
.
. This theory provides a general framework for instructional designers for it allows them to control the conditions of learning, within an environment, or more generally within most instructional materials. Specifically, it provides empirically-based guidelines that help instructional designers to decrease extraneous cognitive load during learning, and refocus that learner's attention toward germane materials, increasing germane (schema related) cognitive load. This theory differentiates between three types of cognitive load: intrinsic cognitive load, germane cognitive load, and extraneous cognitive load.
). This inherent difficulty may not be altered by an instructor. However many schemas may be broken into individual "subschemas" and taught in isolation, to be later brought back together and described as a combined whole.
An example of extraneous cognitive load occurs when there are two possible ways to describe a square to a student. A square is a figure and should be described using a figural medium. Certainly an instructor can describe a square in a verbal medium, but it takes just a second and far less effort to see what the instructor is talking about when a learner is shown a square, rather than having one described verbally. In this instance, the efficiency of the visual medium is preferred. This is because it does not unduly load the learner with unnecessary information. This unnecessary cognitive load is described as extraneous.
Chandler and Sweller introduced the concept of extraneous cognitive load. This article was written to report the results of six experiments that they conducted to investigate this working memory load. Many of these experiments involved materials demonstrating the split attention effect
. They found that the format of instructional materials either promoted or limited learning. They proposed that differences in performance were due to higher levels of the cognitive load imposed by the format of instruction. "Extraneous cognitive load" is a term for this unnecessary (artificially induced) cognitive load.
. It was first described by Sweller, van Merrienboer and Paas in 1998. While intrinsic cognitive load is generally thought to be immutable (although techniques can be applied to manage complexity by segmenting and sequencing complex material), instructional designers can manipulate extraneous and germane load. It is suggested that they limit extraneous load and promote germane load.
Until the 1998 article by Sweller, van Merriënboer & Paas, cognitive load theory primarily concentrated on the reduction of extraneous cognitive load. With this article, cognitive load researchers began to seek ways of redesigning instruction to redirect what would be extraneous load, to now be focused toward schema construction (germane load). Thus it is very important for instructional designers to "reduce extraneous cognitive load and redirect learners' attention to cognitive processes that are directly relevant to the construction of schemas".
Paas and van Merriënboer used relative condition efficiency to compare three instructional conditions (worked examples, completion problems, and discovery practice). They found learners who studied worked examples were the most efficient, followed by those who used the problem completion strategy. Since this early study many other researchers have used this and other constructs to measure cognitive load as it relates to learning and instruction.
The ergonomic approach seeks a quantitative neurophysiological expression of cognitive load which can be measured using common instruments, for example using the heart rate
-blood pressure
product (RPP) as a measure of both cognitive and physical occupational workload. They believe that it may be possible to use RPP measures to set limits on workloads and for establishing work allowance.
Identifying the processing capacity of individuals could be extremely useful in further adapting instruction (or predicting the behavior) of individuals. Accordingly, further research would clearly be desirable. First, it is essential to compute the memory load imposed by detailed analysis of the processes to be used. Second, it is essential to ensure that individual subjects are actually using those processes. The latter requires intensive pre-training.
For ergonomics standards see:
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...
(WM). Theories contend that during complex learning activities the amount of information and interactions that must be processed simultaneously can either under-load, or overload the finite amount of working memory one possesses. All elements must be processed before meaningful learning can continue.
Instruction may be aimed at teaching learners problem solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...
skills, thinking and reasoning skills (including perception, memory, language, etc.). Many would agree that people learn better when they can build on what they already understand (known as existing schemas
Schema (psychology)
A schema , in psychology and cognitive science, describes any of several concepts including:* An organized pattern of thought or behavior.* A structured cluster of pre-conceived ideas....
), but the more a person has to learn in a shorter amount of time, the more difficult it is to process that information in working memory. Consider the difference between having to study a subject in one's native language
Language
Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...
versus trying to study a subject in a foreign language. The cognitive load is much higher in the second instance because the brain must work to translate the language while simultaneously trying to understand the new information.
Another aspect of cognitive load theory involves understanding how many discrete units of information can be retained in short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
before information loss occurs. An example of this principle that seems to be commonly cited is the use of 7-digit phone numbers, based on the theory that most people can only retain seven "chunks" of information
Chunking (psychology)
Chunking, in psychology, is a phenomenon whereby individuals group responses when performing a memory task. Tests where individuals can illustrate "chunking" commonly include serial and free recall, as these both require the individual to reproduce items that he or she had previously been...
in their short-term memory.
Cognitive load theory
"Cognitive load theory has been designed to provide guidelines intended to assist in the presentation of information in a manner that encourages learner activities that optimize intellectual performance". John SwellerJohn Sweller
John Sweller is an Australian educational psychologist who is best known for formulating an influential theory of cognitive load.He has a Ph.D. from the University of Adelaide's Department of Psychology — his thesis was titled "Effects of initial discrimination training on subsequent shift learning...
's theory employs aspects of information processing
Information processing
Information processing is the change of information in any manner detectable by an observer. As such, it is a process which describes everything which happens in the universe, from the falling of a rock to the printing of a text file from a digital computer system...
theory to emphasize the inherent limitations of concurrent working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...
load on learning during instruction. It makes use of schemas
Schema (psychology)
A schema , in psychology and cognitive science, describes any of several concepts including:* An organized pattern of thought or behavior.* A structured cluster of pre-conceived ideas....
as the unit of analysis for the design of instructional materials.
The history of cognitive load theory
The history of cognitive load theory can be traced back to the beginning of Cognitive Science and the work of G.A. Miller. Miller was perhaps the first to suggest our working memory capacity was limited in his classic paper. His experimental results suggested that humans are only able to hold seven plus or minus two digitsThe Magical Number Seven, Plus or Minus Two
"The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information" is one of the most highly cited papers in psychology. It was published in 1956 by the cognitive psychologist George A. Miller of Princeton University's Department of Psychology in Psychological...
of information in their short-term memory. Simon and Chase used the term "chunk" to describe how people might organize information in their short-term memory, this chunking of memory components has also been described as schema
Schema (psychology)
A schema , in psychology and cognitive science, describes any of several concepts including:* An organized pattern of thought or behavior.* A structured cluster of pre-conceived ideas....
construction.
John Sweller
John Sweller
John Sweller is an Australian educational psychologist who is best known for formulating an influential theory of cognitive load.He has a Ph.D. from the University of Adelaide's Department of Psychology — his thesis was titled "Effects of initial discrimination training on subsequent shift learning...
developed cognitive load theory (CLT) while studying problem solving. While studying learners as they solved problems, he and his associates found that learners often use a problem solving strategy called means-ends analysis
Means-ends analysis
Means-Ends Analysis is a technique used in Artificial Intelligence for controlling search in problem solving computer programs.It is also a technique used at least since the 1950s as a creativity tool, most frequently mentioned in engineering books on design methods...
. He suggests problem solving by means-ends analysis requires a relatively large amount of cognitive processing capacity, which may not be devoted to schema construction. Instead of problem solving, Sweller suggests Instructional designers should limit cognitive load by designing instructional materials like worked-examples, or goal-free problems.
In the 1990s, cognitive load theory was applied in several contexts and the empirical results from these studies led to the demonstration of several learning effects: the completion-problem effect; modality effect
Multimedia learning
Multimedia learning is the common name used to describe the cognitive theory of multimedia learning This theory encompasses several principles of learning with multimedia.-The Modality principle:...
; split-attention effect; the worked-example effect
Worked-example effect
The worked-example effect is a learning effect predicted by cognitive load theory . According to Sweller: "The worked example effect is the best known and most widely studied of the cognitive load effects"The worked-example effect is a learning effect predicted by cognitive load theory (Sweller,...
and the expertise reversal effect
Expertise reversal effect
The expertise reversal effect is related to cognitive load theories of learning. It states that guidance provided to experts can hinder their ability to learn: "learners would have to relate and reconcile the related components of available long-term memory base and externally provided guidance...
.
Types
Cognitive load theory has broad implications for instructional designInstructional design
Instructional Design is the practice of creating "instructional experiences which make the acquisition of knowledge and skill more efficient, effective, and appealing." The process consists broadly of determining the current state and needs of the learner, defining the end goal of instruction, and...
. This theory provides a general framework for instructional designers for it allows them to control the conditions of learning, within an environment, or more generally within most instructional materials. Specifically, it provides empirically-based guidelines that help instructional designers to decrease extraneous cognitive load during learning, and refocus that learner's attention toward germane materials, increasing germane (schema related) cognitive load. This theory differentiates between three types of cognitive load: intrinsic cognitive load, germane cognitive load, and extraneous cognitive load.
Intrinsic
Intrinsic cognitive load is the inherent level of difficulty associated with instructional materials. The term was first used by Chandler and Sweller. According to them, all instruction has an inherent difficulty associated with it (e.g., the calculation of 2 + 2, versus solving a differential equationDifferential equation
A differential equation is a mathematical equation for an unknown function of one or several variables that relates the values of the function itself and its derivatives of various orders...
). This inherent difficulty may not be altered by an instructor. However many schemas may be broken into individual "subschemas" and taught in isolation, to be later brought back together and described as a combined whole.
Extraneous
Extraneous cognitive load is generated by the manner in which information is presented to learners and is under the control of instructional designers. This load can be attributed to the design of the instructional materials. Because there is a single, limited cognitive resource, using resources to process the extraneous load reduces the amount of resources available to process the intrinsic load and germane load (i.e., learning). Thus, especially when intrinsic and/or germane load is high (i.e., when a problem is difficult), materials should be designed so as to reduce the extraneous load.An example of extraneous cognitive load occurs when there are two possible ways to describe a square to a student. A square is a figure and should be described using a figural medium. Certainly an instructor can describe a square in a verbal medium, but it takes just a second and far less effort to see what the instructor is talking about when a learner is shown a square, rather than having one described verbally. In this instance, the efficiency of the visual medium is preferred. This is because it does not unduly load the learner with unnecessary information. This unnecessary cognitive load is described as extraneous.
Chandler and Sweller introduced the concept of extraneous cognitive load. This article was written to report the results of six experiments that they conducted to investigate this working memory load. Many of these experiments involved materials demonstrating the split attention effect
Split attention effect
The split-attention effect is a learning effect inherent within some poorly designed instructional materials. It is apparent when the same modality is used for various types of information within the same display...
. They found that the format of instructional materials either promoted or limited learning. They proposed that differences in performance were due to higher levels of the cognitive load imposed by the format of instruction. "Extraneous cognitive load" is a term for this unnecessary (artificially induced) cognitive load.
Germane
Germane cognitive load is that load devoted to the processing, construction and automation of schemasSchema (psychology)
A schema , in psychology and cognitive science, describes any of several concepts including:* An organized pattern of thought or behavior.* A structured cluster of pre-conceived ideas....
. It was first described by Sweller, van Merrienboer and Paas in 1998. While intrinsic cognitive load is generally thought to be immutable (although techniques can be applied to manage complexity by segmenting and sequencing complex material), instructional designers can manipulate extraneous and germane load. It is suggested that they limit extraneous load and promote germane load.
Until the 1998 article by Sweller, van Merriënboer & Paas, cognitive load theory primarily concentrated on the reduction of extraneous cognitive load. With this article, cognitive load researchers began to seek ways of redesigning instruction to redirect what would be extraneous load, to now be focused toward schema construction (germane load). Thus it is very important for instructional designers to "reduce extraneous cognitive load and redirect learners' attention to cognitive processes that are directly relevant to the construction of schemas".
Measurement
Paas and van Merriënboer developed a construct (known as relative condition efficiency) which helps researchers measure perceived mental effort, an index of cognitive load. This construct provides a relatively simple means of comparing instructional conditions. It combines mental effort ratings with performance scores. Group mean z-scores are graphed and may be compared with a one-way Analysis of variance (ANOVA).Paas and van Merriënboer used relative condition efficiency to compare three instructional conditions (worked examples, completion problems, and discovery practice). They found learners who studied worked examples were the most efficient, followed by those who used the problem completion strategy. Since this early study many other researchers have used this and other constructs to measure cognitive load as it relates to learning and instruction.
The ergonomic approach seeks a quantitative neurophysiological expression of cognitive load which can be measured using common instruments, for example using the heart rate
Heart rate
Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
-blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
product (RPP) as a measure of both cognitive and physical occupational workload. They believe that it may be possible to use RPP measures to set limits on workloads and for establishing work allowance.
Individual differences in processing capacity
Evidence has been found that individuals systematically differ in their processing capacity. A series of experiments support the assumption that each individual has a fixed capacity for processing information, irrespective of the task in question, or more accurately, irrespective of the processes an individual uses in solving any given task. Tasks ranged from remembering simple lists, lists supplemented with a fixed constant and simple arithmetic.Identifying the processing capacity of individuals could be extremely useful in further adapting instruction (or predicting the behavior) of individuals. Accordingly, further research would clearly be desirable. First, it is essential to compute the memory load imposed by detailed analysis of the processes to be used. Second, it is essential to ensure that individual subjects are actually using those processes. The latter requires intensive pre-training.
Journal Special Issues
For those wishing to learn more about cognitive load theory, please consider reading these journals and special issues of those journals:- Educational PsychologistEducational psychologistAn educational psychologist is a psychologist with a Master’s degree in Educational psychology An educational psychologist (many countries use this term to signify those who provide services to students, their teachers, and families while other countries use this term to signify academic training...
, vol. 43 (2008) - Applied Cognitive Psychology vol. 20(3) (2006)
- Applied Cognitive Psychology vol. 21(6) (2007)
- ETR&D vol. 53 (2005)
- Instructional Science vol. 32(1) (2004)
- Educational Psychologist vol. 38(1) (2003)
- Learning and Instruction vol. 12 (2002)
For ergonomics standards see:
- ISO 10075-1:1991 Ergonomic Principles Related to Mental Workload – Part 1: General Terms and Definitions
- ISO 10075-2:1996 Ergonomic Principles Related To Mental Workload – Part 2: Design Principles
- ISO 10075-3:2004 Ergonomic Principles Related To Mental Workload – Part 3: Principles And Requirements Concerning Methods For Measuring And Assessing Mental Workload
- ISO 9241ISO 9241ISO 9241 is a multi-part standard from the International Organization for Standardization covering ergonomics of human-computer interaction. It is managed by the ISO...
Ergonomics of Human System Interaction
Further reading
- Cooper, Graham (1998). "Research into Cognitive Load Theory and Instructional Design at UNSW".
- UNSW Cognitive Load Theory Conference - Sydney Australia 24-26 March 2007