Human channel capacity

Cognitive load theory describes how the architecture of cognition has specific implications for the design of instruction. The theory has broad applications in the design of instructional materials, providing a general framework and conceptual toolkit for instructional designers to minimize and control the conditions that create unwanted cognitive load in learning materials.

John Sweller's theory employs an information processing model of cognition, emphasizes the inherent limitations of working memory, and uses schemas as the relevant unit of analysis &mdash; the building blocks &mdash; for instructional materials. His theory differentiates between intrinsic, germane, and extraneous cognitive load.

Intrinsic load relates to the integral complexity of an idea or set of concepts, and reflects the inherent, absolute difficulty of the material to be learned. For example, the mental calculation of 2 + 2 has lower intrinsic load than solving a differential equation. Extraneous load is attributable to the design of the instructional materials, and shows itself as the unnecessary load found in inefficient instructional designs. For example, an audio-visual presentation format usually has lower extraneous load than a visual-only format, because in the former case, working memory has less information to process in the visual modality since the audio modality is also being used to convey information. Germane load relates to the degree of effort involved in the processing, construction and automation of schemas. Germane load is sometimes associated with motivation and interest. Intrinsic load is unchangeable, whereas the instructional designer can manipulate extraneous and germane load. Cognitive load theory is often used as the basis for educational multimedia presentation.