Cognitive load
In cognitive psychology, cognitive load is the effort being used in the working memory. According to work conducted in the field of instructional design and pedagogy, broadly, there are three types of cognitive load:
- Intrinsic cognitive load is the effort associated with a specific topic.
- Germane cognitive load refers to the work put into creating a permanent store of knowledge.
- Extraneous cognitive load refers to the way information or tasks are presented to a learner.
Cognitive load theory was developed in the late 1980s out of a study of problem solving by John Sweller. Sweller argued that instructional design can be used to reduce cognitive load in learners.
Much later, other researchers developed a way to measure perceived mental effort which is indicative of cognitive load. Task-invoked pupillary response is a reliable and sensitive measurement of cognitive load that is directly related to working memory. Information may only be stored in long-term memory after first being attended to, and processed by, working memory. Working memory, however, is extremely limited in both capacity and duration. These limitations will, under some conditions, impede learning. Heavy cognitive load can have negative effects on task completion, and the experience of cognitive load is not the same in everyone. The elderly, students, and children experience different, and more often higher, amounts of cognitive load.
The fundamental tenet of cognitive load theory is that the quality of instructional design will be raised if greater consideration is given to the role and limitations of working memory.
With increased distractions, particularly from cell phone use, students are more prone to experiencing high cognitive load, which can reduce academic success.
Theory
In the late 1980s, educational psychologist John Sweller developed cognitive load theory out of a study of problem solving, in order "to provide guidelines intended to assist in the presentation of information in a manner that encourages learner activities that optimize intellectual performance". Sweller'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 the schema as primary unit of analysis for the design of instructional materials.History
The history of cognitive load theory can be traced to the beginning of cognitive science in the 1950s and the work of G. A. Miller. In his classic paper, Miller was perhaps the first to suggest our working memory capacity has inherent limits. His experimental results suggested that humans are generally able to hold only seven plus or minus two units of information in short-term memory.In 1973 Simon and Chase were the first to use the term chunk to describe how people might organize information in short-term memory. This chunking of memory components has also been described as schema construction.
In the late 1980s Sweller developed cognitive load theory while studying problem solving. 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. Sweller suggested that instructional designers should prevent this unnecessary cognitive load by designing instructional materials which do not involve problem solving. Examples of alternative instructional materials include what are known as worked examples and goal-free problems.
In the 1990s, cognitive load theory was applied in several contexts. The empirical results from these studies led to the demonstration of several learning effects: the completion-problem effect; modality effect; split-attention effect; worked-example effect; and expertise reversal effect.
Categories
Cognitive load theory provides a general framework with broad implications for instructional design by focusing on the limitations of human working memory as a central constraint on learning. The primary aim of the theory is to guide the effective use of this limited cognitive resource by structuring learning conditions and instructional materials in ways that reduce extraneous cognitive load and optimize intrinsic cognitive load. By doing so, instructional designers can better direct learners’ attention toward essential information and processes that support schema construction, thereby increasing germane cognitive load. Cognitive load theory distinguishes among three types of cognitive load: intrinsic, extraneous, and germane cognitive load.Intrinsic
Intrinsic cognitive load is the inherent level of difficulty associated with a specific instructional topic. The term was first used in the early 1990s by Chandler and Sweller. According to them, all instructions have an inherent difficulty associated with them. 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.Germane load
Germane load refers to the working memory resources that the learner dedicates to managing the intrinsic cognitive load associated with the essential information for learning. Unlike intrinsic load, which is directly related to the complexity of the material, germane load does not stem from the presented information but from the learner's characteristics. It does not represent an independent source of working memory load; rather, it is influenced by the relationship between intrinsic and extraneous load. If the intrinsic load is high and the extraneous load is low, the germane load will be high, as the learner can devote more resources to processing the essential material. However, if the extraneous load increases, the germane load decreases, and learning is affected because the learner must use working memory resources to deal with external elements instead of the essential content. This assumes a constant level of motivation, where all available working memory resources are focused on managing both intrinsic and extraneous cognitive load.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, the number of resources available to process the intrinsic load and germane load is reduced. Thus, especially when intrinsic and/or germane load is high, 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. 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 cognitive load.
Extraneous cognitive load may have different components, such as the clarity of texts or interactive demands of educational software.
Measurement
As of 1993 Paas and Van Merriënboer had 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, taking into account both mental effort ratings and performance scores. Relative condition efficiency is calculated by subtracting standardized mental effort from standardized performance and dividing by the square root of two.Paas and Van Merriënboer used relative condition efficiency to compare three instructional conditions. 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 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.
There is active research interest in using physiological responses to indirectly estimate cognitive load, particularly by monitoring pupil diameter, eye gaze, respiratory rate, heart rate, or other factors. While some studies have found correlations between physiological factors and cognitive load, the findings have not held outside controlled laboratory environments. Task-invoked pupillary response is one such physiological response of cognitive load on working memory, with studies finding that pupil dilation occurs with high cognitive load.
Some researchers have compared different measures of cognitive load. For example, Deleeuw and Mayer compared three commonly used measures of cognitive load and found that they responded in different ways to extraneous, intrinsic, and germane load. A 2020 study showed that there may be various demand components that together form extraneous cognitive load, but that may need to be measured using different questionnaires.