2. Accidents. & Errors. Flashcards
Norman - routine vios
when it is so often it is ignored. ex.: routine shortcuts = vio of procedure
Norman - situational vios
vio under special circumstances. ex.: drive fast because you need to get something
Norman - slips
when someone intends to perform one action, but performs another
Norman - action-based slips
wrong action is performed. ex: put milk in coffee then put coffee cup in fridge instead of milk -> didn’t mean to do that
Norman - memory-lapse slips
intended action is not performed or the results are not evaluated. ex.: forget to turn off gas stove/forget locking door. -> i forgot
Norman - mistakes
wrong goal is set or wrong plan is formed
Norman - rule-based mistakes
good diagnosis of situation, followed wrong rules to base the action. ex.: choosing incorrect procedure/failure to identify risk -> that was the wrong choice
Norman - knowledge based mistakes
wrong diagnosis of problem due to incomplete knowledge. ex.: weighing something in pounds instead of kgs. -> i did not know what i was doing was wrong
Norman - memory-lapse mistakes
when something is forgotten in the goals, plans or evaluation stages. ex.: when mechanic can’t complete everything because he is distracted/skipping step in procedure because you’re doing 2 things at once.
Norman - capture slips
situation where, instead of action, a more frequent action is performed: it records the activity. ex.: leave house and walk to school instead of supermarket
Norman - description similarity slips
error is to respond to an item that is similar to target. ex.: pouring oj in cereal/putting wrong lid on bowl
Norman - memory-lapse slips
immediate cause are interruptions. ex.: forgetting phone/driving with coffee cup on top of the car
Norman - mode-error slip
when a device has different states/modes, causing control to have different meanings. ex.: When an electric guitar is turned off by a switch, if you don’t turn the switch back on, the electric guitar will have a diff sound
Norman - skill-based mistakes
occurs when workers are extremely expert at their jobs, so they can do the everyday routine tasks with little or no thought or conscious attention.
More of a slip
Norman - rule-based mistakes
Diagnose the situation but decide to take the wrong action, (wrong rule is followed)
Eg. go to change your clothes, instead of putting clothes to go out you put on your pj’s
Norman - knowledge-based mistakes
occur when unfamiliar events occur, where neither existing skills nor rules apply.
Eg. weighing of fuel computed in pounds instead of kgs
Norman - memory-lapse mistakes
mistakes due to memory failure to forget goal/plan; due to interruption.
when there is forgetting in-between stages of goals
Disturbe sequence of the action (diff than slips) → happens in higher levels
Norman - design lessons from errors
adding constraints to block errors, undo, confirmation and error messages, make item more prominent, make operation reversible, sensibility checks, minimizing steps
Norman - swiss cheese model
Each slice of cheese represents a condition in the task that needs to be done, an accident can only happen if holes in all the slices of cheese are exactly on the same line. Therefore, it is difficult to look for “the cause” of an accident because it has been preceded by several exactly matching errors. Several ways to reduce accidents are:
- Ensuring more slices of cheese; thus, more defenses;
- Reducing the number of gaps by, for example, better equipment;
- Alerting operators when several holes line up.
Reason - person approach
focus on unsafe acts of people. cause: forgetfulness, inattention, poor motivation etc. just world hypothesis
Reason - system approach
humans are fallible and errors can be expected. error is consequences with origin in systemic factors.
Reason - swiss cheese model
Defenses, barriers, and safeguards occupy a key position in the system approach. o The function is to protect potential victims and assets from local hazards. Most do that effectively, but there are always weaknesses.
• In an ideal world, each defensive layer would be intact. However, they are more like slices of
Swiss cheeses, having many holes. The presence of wholes does not normally cause a bad outcome. Only when the
holes in multiple layers line up at the same time to allow an accident trajectory can
this happen. Active failures = unsafe acts committed by people who are in direct contact with the patient or system.
▪ Direct and short-lived impact on the integrity of defenses.
▪ At Chernobyl, for example, the operators wrongly violated plant procedures
and switched off successive safety systems, thus creating the immediate
trigger for the catastrophic explosion in the core.
▪ Followers of the person approach often look no further for the causes of an adverse event once they have identified these proximal unsafe acts
Latent condition = arise from decisions made by designers, builders procedure writes, and top-level management.
▪ Inevitable resident pathogens (virus) within the system.
▪ May be latent for years within the system before combining with active
failures and local triggers to create an accident opportunity.
• Unlike active failures, which can take a variety of forms that are
difficult to predict, latent circumstances can be detected and corrected before a negative event happens. This knowledge leads to proactive risk management rather than reactive risk management.
• Latent conditions have two kinds of adverse effects:
o They can translate into error provoking conditions within the local workplace; time
pressure, understaffing, inadequate equipment, fatigue, inexperience
o They can create long-lasting holes or weaknesses in the defenses; untrustworthy
alarms and indicators, unworkable procedures design, and construction deficiencies
Reason - error management
Error management has two components:
o Limiting the incidence of dangerous errors;
o Creating systems that are better able to tolerate the occurrence of errors and
contain their damaging effects.
• High-reliability organizations – systems operating in hazardous conditions that have fewer
than their fair share of adverse events – offer important models for what constitutes a resilient system.
o Has intrinsic safety health: is able to withstand its operational dangers and yet still achieve its objective.
Day - goal study
study relationship between level of cognitive failure and individual, psychological stress and workplace accidents
Day - results H1
people in accident group more stress + more psychological strain. & higher reported cognitive failure. so, individuals with an accident in the navy have high levels of psychological stress and daily failure.
Day - results H2
people who score high on levels of psychological stress (ghq) are more prone to an accidents, cognitive functioning mediates this. high scores on daily failure task, so fail a lot are the processes by which high stress determines whether or not there is an accident. so, elevated stress = probably more accidents because prone to cognitive errors.
Day - conclusion
high cfq scores indicates increased vulnerability when work demands are high. those with psychological stress more likely to have an accident because of increased susceptibility to cognitive errors. best to hire stress-resistant people and lower work demands
Hansen - introversion and extroversion
intro: less accidents, more control
extro: more accidents and safety vios.
Hansen - assumptions about accidents
- determinants of accidents are multiple, only a part attributable to personality. 2. number of personality trait, some unrelated to another, related to accidents. 3. people rarely repeat accidents.
Hansen - locus of control
external: more involved in accidents
internal: actively try to prevent accidents
Hansen - aggression
part of a set of traits consistently associated with accidents
Hansen - social maladjustment
combination of behaviors is often found and associated with high accidents rate. (sociopaths attitudes, immaturity, irresponsiblity etc.)
Hansen - neurosis
social maladjustment more distressing because person’s attention is diverted from task, neurosis correlated with accidents. + multidimensional, only some parts related to accidents: depression, guilt and anxiety
Hansen - impulsivity
more reckless and more accidents
Hansen - taking risks
experiences workers, older workers and female workers take fewer risks than inexperienced, young, male workers.
Hansen - conclusion
o There is much evidence that locus of control is related to accidents, especially external locus
of control.
o Extraversion is strongly related to high accident rates.
o Aggression is strongly and repeatedly associated with accidents.
o There is much evidence that social maladjustment is not only related to incidents but is
probably a primary factor in accident causation.
o There appears to be an association between general neurosis and accidents.
o Specific neurotic disorders such as anxiety and depression have ( in the few studies on these
topics) been associated with accidents.
o There is consistent and reasonably strong evidence to link impulsivity to accidents. o The research is too thin to conclude anything about risk-taking and accidents.
Christian - goal study
personal and situational antecedents of safety performance and safety outcomes
Christian - person-related proximate antecedents
safety knowledge and safety motivation: willingness to make an effort to perform safety behaviors
Christian - person related distal antecedents
conscientiousness: more trustworthy, neuroticism, extraversion, locus of control, propensity for risk taking, job attitudes
Christian - situation related distal antecedents
psychological safety climate: individual perception of policies and group-level safety climate: shared perception work environment and leadership
Christian - results proximal person-related factors
safety performance strong with safety knowledge & motivation. safety motivation strong with compliance.
Christian - results distal person related factors
partial support safety performance (moderate to locus of control, weakly to C). job attitudes weakly to safety performance (support). locus of control stronger with safety participation (support). partial support for C, N, locus of control and job attitudes weakly to safety outcomes.
Christian - distal situation related factors
support overall safety climate and performance. leadership relationship with safety performance supported; strong with safety participation than with compliance and average relation with safety performance + weak with accidents. psychological climate more to participation same for leadership. leadership weakly to safety outcomes. FIGURE.
Christian - model
all direct paths were significant, so support for full mediation model. support for the framework.
Christian - conclusion
Safety climate was positively related to both safety knowledge and safety motivation, whereas conscientiousness was positively associated with just safety motivation. Safety motivation was related to safety knowledge, and both of these variables were positively related with safety performance.
→Safety performance was correlated with accidents and injuries.
Christian - results
- Proximal variables are higher correlated than distal variables: this is true for safety performance but not for safety outcomes.
- In general, evidence for the model was found.
- Safety climate is positively related to safety knowledge and to safety motivation.
- Conscientiousness is only positively related to safety motivation.
Safety motivation is related to safety knowledge and both are positively related to safety performance. - Safety performance is negatively correlated with accidents and injuries. The following figures show the results found:
• Safety knowledge and safety motivation exhibited stronger effects for the safety performance than any of the distal factors.
• No support for safety outcomes
o Distal factors had stronger magnitudes than the proximal factor safety knowledge.
Frese - error management perspective
pointless to prevent all errors from occuring. add-on strategy. through design, training, prevention works by blocking erroneous. starts after error occurred and attempts to block negative error consequences
Frese - avoiding or reducing negative error consequences
reducing changes or error cascade: one error leading to the next. systems damage control, organizations’ and teams’ damage control. damage control within the social realm: re-establishing trust and gaining forgiveness
Frese - positive outcomes of error management
learning from errors. emotional processes associated with learning from errors. motivational processes associated with learning from errors: intrinsic motivation and learning goal orientation. cognitive processes and behavioral activities associated with learning from errors. learning from errors with minor versus major negative consequences
Frese - negative outcome bias
more attention is paid to and more learning is instigated by events with more negative outcomes.
Error management and performance
Error management training leads to learning and improved performance.
