Overview
Cognitive load refers to the strain or burden put onto someone’s working memory.
History and Etymology
The idea of humans having limited mental bandwidth has been observed for a long time. Modern cognitive psychology has been interested in measuring the limits and mechanisms of that bandwidth and related capacities. In 1956, George Miller published a study that found our short-term memory is generally limited to holding about five to nine items at a time. In 1968, Richard Atkinson and Richard Shiffrin proposed a model of information flow through sensory memory, working memory, and long-term memory. Herbert Simon and William Chase published a 1973 study that examined the patterns of Chess Grandmasters to conclude that they organized blocks of pieces into chunks, or “schemas”, rather than looking at each piece individually. Educational psychologists were particularly interested in exploring the way models of the world are created, updated, and applied. Richard Anderson used the concept of schemas to show that reading comprehension is heavily driven by prior context about the world a reader has developed. David Rumelhart furthered the idea of using schemas to navigate the world in 1980 by proposing a theory that schemas are fundamental building blocks of intelligent cognition which allows minds to navigate the world without becoming overwhelmed by sensory input and information.
Cognitive Load Theory (CLT) was developed into a formal framework in 1988 by John Sweller. While studying the way students approached math and science problems, he noticed that the trial-and-error approach of problem-solving that worked when navigating daily life consumed massive amouts of mental energy, so students often didn’t have the capacity left to internalize an abstract concept after completing a problem. He and other researchers delineated a few categories of cognitive load:
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Intrinsic Load: how difficult a topic is to learn on its own. College-level math courses will almost certainly register as inherently difficult for most people relative to the abstractions and operations needed for their daily lives.
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Extraneous Load: how difficult the environment makes it to learn the topic. If you have an apathetic teacher, obnoxious classmates, or a hungry stomach, you have a variety of factors that can make it difficult to learn topics that have a low intrinsic load
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Germane Load: how much effort it takes to build long-term schemas by building relationships between past knowledge and new information. A topic might be easy to learn and a stellar learning environment may be accessible for a student, but if the material is only presented through extremely dense texts or complicated software, the student has to expend extra effort to allocate attention to the medium of the information itself. They might have to remember how to use the software at the same time that they’re trying to connect the material presented within it.
In practice, these forms of cognitive load are considered to be interconnected with significant overlap in their mechanisms.