Cognitive Load

The term cognitive load is used in cognitive psychology to illustrate the load related to the executive control of working memory (WM).

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.

Intrinsic cognitive load

The term "intrinsic cognitive load" was first described by Chandler and Sweller. Accordingly all instruction has an inherent difficulty associated with it (e.g., the calculation of 2 + 2, versus solving a differential equation). 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 cognitive load

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 visual and should be described using a visual 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 cognitive load.

Germane cognitive load

Germane load is that load devoted to the processing, construction and automation of schemas. While intrinsic load is generally thought to be immutable, instructional designers can manipulate extraneous and germane load. It is suggested that they limit extraneous load and promote germane load.