This weeks reading discusses the theory of “Performance Load”, the “degree of mental and physical activity required to achieve a goal”. The reading states Performance Load consists of 2 types of loads: Kinematic Load and Cognitive Load.
Cognitive load theory suggests when users are bombarded with information, due to a shortage of working memory, overall usability is decreased thus resulting in lower than desired user performance. (Sweller, 1988).
According to David Lewis “Cognitive load theorists distinguish between three types of load: intrinsic, extraneous and germane cognitive load.” (Lewis, 2010). Intrinsic cognitive load is defined by the characteristics of the information, instead of the way in which it is presented. (Lewis, 2010). Extraneous cognitive load is in which way the information is presented. (Chandler & Sweller, 1991; Chandler & Sweller, 1992).The presentation of information is vital and must not detract from the underlying information. Germane (or Relevant) load is any free thinking capacity that can be used to deal with any irrelevant information. (Sweller, 1988)
Kinematic load is the measurement of physical actions, which must be undertaken to accomplish a task. (Lidwell, Holden, Butler, 2003). A reduction in Kinematic load results in easier fulfillment of tasks and outcomes. Decreasing unnecessary steps within a task reduces the expenditure of Kinematic load, thus aiding in an easier completion.
Chunking is listed as a strategy of reducing cognitive load, resulting in increased performance time and a decreased chance of error. Chunking is the process of grouping together similar ideas, to decrease information bombardment and overall randomness of a design. When similar initiatives are grouped together, it eliminates the chance of the user spending a considerable amount of time searching for relating ideas.
Chunking is of considerable use when users are required to remember long strands or massive amounts of information. If information is grouped, the recalling of one particular idea can provoke the recollection of another. (Cherry, n.d.).
When a visual design utilizes the chunking method, communication can be increased. Instead of communication several related ideas separately, chunking can communicate them as one, similar idea. This increases user comprehensibility and decreases the time needed to communicate large amounts of information.
In 2003, Lidwell, Holden and Butler stated that ‘The term chunking seeks to accommodate short-term memory limits by formatting information into a small number of units’. This is exemplified within visual communication, predominantly in hierarchical design, which suggests grouping similar ideas to reduce userssearch time.
The utilization of chunking is important in reducing both cognitive and kinematic load. Less time needs to be spent memorizing information, thus performance and user satisfaction can be increased.
Due to the intrinsic nature the cognitive thought process plays on the digestion and learning of information, the study of psychology is essential to further understand just how cognition is achieved.
Lidwell, Holden and Butler stated that information reception is increased by a decrease in cognitive and kinematic load. (2003). As visual design is a method of projecting information to an audience, the study of Performance load, and how to ensure it can be as minimal as possible is necessary. Without psychological insight into performance load, and by extension, information processing, understanding the methods behind increased user performance would not be possible.
Sweller, J. (1988). Cognitive load during problem solving: Effects on learning. Cognitive Science, 12(2), 257-285.
Lewis, D. (2010). Cognitive Load Theory.KNOL(9).
Chandler, P. & Sweller, J. (1991). Cognitive load theory and the format of instruction.Cognition and Instruction.8(4), 293-332.
Chandler, P., & Sweller, J. (1992). The split-attention effect as a factor in the design of instruction.British Journal of Educational Psychology, 62, 233-246.
Cherry, K. About.Com. Physchology. What is Chunking?, from http://psychology.about.com/od/cindex/g/chunking.htm
Lidwell, W., Holden, K., & Butler, J. (2003). Performance Load. In Universal Principles of Design (pp. 148‐149). Massachusetts: Rockport.