Understanding the role of the
human factor in safety critical
systems
Dr Lisa Hinkley
Department of Psychology
Oxford Brookes University
Human Factors Psychology
• The study of those variables that influence the
efficiency with which the human performer can
interact with the inanimate components of a
system to accomplish the system goals
– (Proctor & van Zandt, 1994, p.2)
• Human factors works to apply principles of
psychology to designing products and
creating work environments that boost
productivity while minimizing safety issues.
Important Topics in Human
Factors Psychology
• Cognitive:
– Perception
– Attention span
– Memory span
• But also:
– Social psychological issues
– Physical limitations
Human Factors Psychology
• Applied to:
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Military technology
Nuclear power plants
Aviation
Automobiles
Medicine
• Safety critical, consequences of error???
– Consumer products
• e.g. labelling of produce
– Human-computer interaction
• Not necessarily be life threatening – but frustrating!
How?
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Use what we know about human information
processing to aid system design:
• Examine how users perform task – aid design
• Consider every potential user, not just young, techsavvy people with perfect vision
• Anticipate common mistakes the user might make
and prevent those mistakes
• Nothing the user does should result in a
catastrophic error.………Ever
Goal – improve human/machine interaction
• Most of the time, if you make a mistake using a
product, it’s a design flaw, not a human flaw
Human Factors &
Misperceptions
• Understanding human
factors enables us to
design equipment to
prevent disasters.
• 80% airline crashes
caused by human error
– errors of perception?
Previous Projects
• Human Factors in Aviation Security
– DERA & Department of Transport
• X-ray screeners – how do they make decision
– re: baggage & passengers
• Safety critical – September 11 attacks
– Cognitive factors:
• Perceptions, attention, decision making
– Social factors:
• Peer pressure, airport bosses etc.
• MR-tutor
– provide a computer-based training tool for
neuroradiology trainees.
– provide statistical support for the classification
/diagnosis of MR-images of the brain
Bad Icon Design
http://www.baddesigns.com
Remote control
How do you turn down the volume?
The Infamous Ballot
Some human factors issues to consider:
1. The side-by-side presentation is confusing.
2. No consideration of even minimal visual impairment.
3. No consideration of even minimal motor impairment.
4. Why is it possible to punch two if you can only vote for
one?
5. It presents extraneous information (e.g., the numbers).
Safety Critical???