Perspectives for Undestanding Human Performance and Error
Over the years a number of models have been developed to understand how human error and performance can contribute to efficiency and health and safty performance . Douglas Wiegmann and Scott Shappell grouped these numerous models under six different perspectives “based on the underlying assumptions made (by each perspective) about the nature and causes of human (performance and) error” (2005, p.20). They conclude that although these perspectives are helpful, they illustrate that there is little consensus with regard to what human error is and what causes it. They propose that more unified theories taking the best from each of the six perspectives would be more useful for understanding human error and performance and suggest that Reason’s ‘Swiss Cheese Model’ offers a more inclusive perspective of human error and its contributions to accident causation.
The overriding principle of the Cognitive Perspective is that the pilot’s mind is an information processing system, somewhat like a computer. Cues or stimuli from the environment being detected by the pilot’s scenes and then processed through working and long-term memories, via a series of mental activities, to produce a response. Errors arise because stimuli may be weak or misleading, resulting in erroneous assessments, or assessments may be correct, but the wrong solution maybe chosen, or the correct solution may be decided upon, but the pilot may not possess the expertise to avoid an error.
This perspective takes the view that pilots are rarely the sole cause of errors or accidents; pilot performance being coupled with other elements in the system; rules, their aircraft, the environment and other operators. Errors occur due to mismatches between elements in the system. The SHEL and later SHELL models are the most commonly cited ergonomic or systems models.
The Behavioural Perspective is based on the idea that pilot performance is focused on the need to obtain rewards, and avoid punishment or disagreeable occurrences. Performance is therefore dependent on a pilot’s motivation as well as their ability.
Based on traditional medical models, this perspective is formulated on the idea that errors are the result of underlying mental or physiological conditions which are ‘triggered’ by environmental conditions or circumstances to create the errors or accidents.
This perspective takes a more humanistic view of error and sees operations as primarily a social endeavour involving numerous interactions between different operators such as pilots, air-traffic controllers, and dispatchers. Performance is directly related to the nature and quality of the interactions between performers in the system. The Relational Coordination Model developed by Jody Gittell (2003) illustrates the influence that positive social interactions can have, but perhaps the best know psychosocial method used in aviation is Crew Resource Management (CRM).
The Organisational Perspective understands the complex nature of performance and error; that it is not just operators and their equipment that are involved. The perspective places an emphasises on the fallibility of the decision making of an organisation’s managers and supervisors.
The six perspectives noted above share little in the way of consensus. Each having advantages and disadvantages for understanding pilot error and accident causation. Several academics, experts and researchers in the fields of safety and human factors have proposed unified theories, but the one most often cited is James Reason’s Model of Accident Causation (1990).
Want to know more?
- Human Error
- An introduction to Human Error.