Cognitive ergonomics

Draft

Definition

• Cognitive Ergonomics studies cognition in work settings, in order to optimize human well-being and system performance. ( Wikipedia )

• “Cognitive ergonomics has to do with how we perceive information and make decisions.” (MacLeod, 2006).

• “Ergonomics is sometimes described as "fitting the system to the human," meaning that through informed decisions; equipment, tools, environments and tasks can be selected and designed to fit unique human abilities and limitations.... Cognitive ergonomics, on the other hand, focuses on the fit between human cognitive abilities and limitations and the machine, task, environment, etc. Example cognitive ergonomics applications include designing a software interface to be "easy to use," designing a sign so that the majority of people will understand and act in the intended manner, designing an airplane cockpit or nuclear power plant control system so that the operators will not make catastrophic errors.” (Budnick and Michael, 2001).

See also: cognitive artifacts, cognitive tools, task environment.

Rules

Successful ergonomic interventions in the area of cognitive tasks require a thorough understanding, not only of the demands of the work situation, but also of user strategies in performing cognitive tasks and of limitations in human cognition. In some cases, the artifacts or tools used to carry out a task may impose their own constraints and limitations (e.g., navigating through a large number of GUI screens); in fact tools co-determine the very nature of the task. In this sense, the analysis of cognitive tasks should examine both the interaction of users with their work setting and the user interaction with artifacts or tools; the latter is very important as modern artifacts (e.g., control panels, software, expert systems) become increasingly sophisticated. - ( Wikipedia - 16:45, 9 June 2006 (MEST) )

MacLoad's webpage identifies the following ground rules:

• Standarize, i.e. ensure that similar devices work the same way.
• Use stereotypes. A stereotype in this context is a commonly held expectation of what people think is supposed to happen when they recognize a signal or activate a control.
• Link actions with perceptions, i.e aim for compatibility between a display of information and a control. In other words, an item should "tell" a person what he is supposed to do.
• Present information in appropriate detail (neither too much, neither not enough).
• Simplify presentation of information.
• Present clear images, i.e. the message should be visible, distinguishable from sourrounding information and interpretable.
• Use redundancies
• Use patterns, e.g. charts instead of numbers,
• Provide variable stimuli (to avoid that users' senses fatigue)
• Provide instantaneous feedback (this is also helps to prevent misunderstandings).

It does seem to DSchneider that some of these guidelines may conflict (Authors' who will write this article may look into this ...

Models and Methods

Cognitive ergonomics has developped methods to design and evaluate new devices, particularly computer-supported ones, that have been the main focus of interest of cognitive ergonomics for the last twenty years.

Recent models of cognitive ergonomics involve three dimensions: usefulness, usability, and acceptance.

The methods used in cognitive ergonomics can be distinguished according to the phases of the design process to which they refer.

Design phase

Cognitive ergonomics is promoting "user-centered design", in the sense that users are integrated in the design process as early as possible.

• “User centred design addresses early and continuous focus on users, empirical measurements, iterative design and multidisciplinary design teams.” (Turkka Keinonen, 2005, [Usability of Interactive Products]).

Examples of methods:

• focus groups: see [fiche sur le site l'ergonome.com]
• socio-cognitive analysis: Interviews and observations aiming at defining representations, attitudes and practices
• activity analysis: set of methods aiming at extracting the "real" activity of users (story telling, critical incidents, "why-how methods" and formalisms to describe it, like MAD

Mireille eventually I will tell a lot more on that!

Evaluation phase

User centered design involves iterative design, so that evaluation is conducted at every stages of development. Most evaluation methods aims at evaluating usability and thus are described under the usability article

Mireille The edition of this section is in progress

Links

• European Association of Cognitive Ergonomics (EACE)
• Human Factors and Ergonomics Society

References

• Peter Budnick and Rachel Michael (2001), What is Cognitive Ergonomics, Ergonomics Today (Ergoweb.com). HTML, retrieved 16:45, 9 June 2006 (MEST).

• Long, J. 1987, Cognitive ergonomics and human±computer interaction, in P. Warr (ed.), Psychology at Work (Harmondsworth, Middlesex, UK: Penguin).

• MacLeod, Dan (2006), Cognitive Ergonomics, Making Sense with Design, HTML, retrieved 16:45, 9 June 2006 (MEST).

• Norman, D. A. (1993). Things that Make Us Smart. New York: Addison Wesley Company.