Test 1, Human Errors Flashcards
What is human error?
It is evident that human reliability is too often (some would argue always) the weak link in the chain of events which leads to loss of safety and catastrophic failure of even the most advanced technological systems. -B.A. Sayers (1988)
What is a slip?
failure in execution of action
Intended behavior is appropriate, but is not carried out correctly, i.e. the user has the right intention but does the wrong thing. Are especially likely to occur when a familiar or automatic behavior must be inhibited
E.g. writing the wrong year on a check, putting car into drive when it should be in reverse
What is a mistake?
errors in planning of action
Intended behavior is inappropriate under the circumstances
A person makes a poor decision, misclassifies a situation, or fails to take all the relevant factors into account
E.g. deciding to let a flight take off despite knowledge of potentially dangerous weather
What is a lapse?
an intended action is forgotten and not carried out
The result of memory failures such as losing track of your place in a sequence of actions
E.g. failing to attach files in an email
What are mode errors?
action is appropriate in one system mode, but is carried out in a different mode
Failing to put car back into drive after backing up a little bit
Typing in Overwrite mode instead of Insert mode
What is error of omision?
the user fails to perform the required action
Error of Commission
the user performs an inappropriate action
Timing Error: Performs an action too early/late
Sequence Error: Performs the steps in the wrong order
Selection Error: Uses the wrong control
Input error
information from the sensory and perceptual processes
Mediation error
cognitive processes that translate between perception and action
Output error
due to the selection and execution of physical responses
Operating Error
a system is not used according to correct procedure
Design Error
system designer creates an error-likely situation by failing to consider human tendencies or limitations
A stressor is anything which:
Is not an inherent characteristic of the human/machine system
Is not inherent in the information to be processed
Is (usually) expected to degrade system performance
Environmental stressors
may include noise, extreme temperature, vibration, poor light
Psychological stressors
might include anxiety, frustration, fatigue
