Human factors Flashcards
What are the 3 categories of error?
- Skill based error
- Thinking error
- Violation
What are the two types of skill based error?
Slips
Lapses
What are the two types of thinking error?
Rule based
Knowledge based
What are the 3 types of non-compliance / violation error?
- Routine
- Situation
- Exceptional
What is a slip and give examples
Not doing what you are meant to do - skill based action inappropriate for the situation. Error of doing something (commision)
e.g. flashing headlight instead of using windscreen washer, take reading from wrong instrument
What is a lapse and give examples
Skill or task omitted /forgotten to do. Error of not doing something (omission)
e.g. forget to indicate at junction, forget to disconnect charge from charger before pulling off
Describe slips and lapses and how they occur
Occur in very familiar tasks which we can carry out without much conscious attention
These tasks are very vulnerable to slips and lapses when our attention is diverted even for a moment.
How can we reduces slips and lapses? (5)
- Checklists
- Reduce distractions
- Human centred designs e.g. intuitive/user friendly
- Warnings/alarms
- Allow sufficient time to complete tasks
Describe how thinking errors / mistakes occur?
Decision making failure, doing what you intended/planned but it is the wrong course of action
What is a rule based error and give examples?
Behaviour is based on remembered rules and procedures, mistake
occurs due to mis-application of a good rule or application of a bad rule:
e.g. misjudge overtaking manoeuvre in unfamiliar, under-powered car
- assume £20 fuel will last a week but fail to account for rising prices
- ignore alarm in real emergency, following history of spurious alarms
What is a knowledge based mistake and give examples?
Individual has no rules or routines available to handle an unusual situation: resorts to first principles and experience to solve problem:
e.g rely on out-of-date map to plan unfamiliar route
- misdiagnose process upset and take inappropriate corrective action
(due to lack of experience or insufficient / incorrect information etc.)
How can we reduce thinking errors? (6)
- plan for ‘what ifs’
- regular drills/exercises for emergencies
- clear overview / mental model (system feedback; effective shift handover etc.)
- diagnostic tools and decision-making aids
- competence (knowledge and understanding of
system; training in decision-making techniques) - organisational learning
What are violations/ non-compliance errors?
Deliberate deviations from rules, procedures, regulations. Knowingly take short cuts
What is a routine non-compliance error/violation and give examples?
Becomes the ‘norm’; general consensus that rules no
longer apply; characterised by a lack of meaningful enforcement:
e.g high proportion of motorists drive at 80mph on the motorway
What is a situation non-compliance error/violation and give examples?
Non-compliance dictated by situation-specific factors (time pressure;
workload; unsuitable tools & equipment; weather)
e.g van driver has no option but to speed to complete day’s deliveries
What is an exceptional non-compliance error/violation?
Person attempts to solve problem in highly unusual circumstances (often if something has gone wrong); takes a calculated risk in breaking rules:
e.g. after a puncture, speed excessively to ensure not late for meeting
How do you reduce non-compliance error/violations? (4)
- improve risk perception
- increase likelihood of getting caught
- eliminate reasons to cut corners
- improve attitudes / organisational culture
What is ‘anchoring bias?’
Being excessively influences by one element of the presented information, which subsequently biases the interpretation of the later information
What is availability bias?
Choosing a particular diagnosis/interpretation because it is at the front of mind (including frequency and recency bias)
What is premature closure?
Arriving at a conclusion or diagnosis before all the options have been considered
What is confirmation bias?
Seeking or prioritising information that confirms current or desired thinking rather than considering all the information
What is framing effect?
The order or way with which initial information is presented ‘frames’ or biases the way subsequent information is interpreted
What is commission bias?
The tendency to act rather than not to act, hence motivating unneeded treatments or actions.
What is overconfidence bias?
The common tendency to believe we know more than we do, or that we are all better-than-average practitioners. May lead to action based on incomplete information
or hunches, rather than carefully gathered evidence.
What is omission bias?
Tendency not to act when intervention is indicated, for example a hesitancy to initiate emergency measures because of worries about being wrong or harming the patient.
Describe the ‘sunk costs’
Unwillingness to give up on a poor conclusion or diagnosis as much time or resource has been invested in developing it
What are the 7 pillars of clinical governance?
- Service user involvement
- HR management
- Personal and professional development
- Clinical effectiveness
- Clinical audit
- Risk management
- Clinical information management
What is a latent failure?
Failure that may have occurred in the past and lay dormant i.e. error made in aircraft design
What is an active failure?
Failure that occurs at the time by front line personnel
What 4 factors effect (cognitive) workload?
- ‘Difficulty’ of the task
- Number of tasks running in parallel (concurrently)
- Number of tasks in series (switching from task to task)
- The time available for the task (speed of task)
What is the:
1. Visual spatial sketchpad
2. Phonological loop
3. What are they used for
2 short term memory buffers that act to buffer sounds and pictures to protect central executive
- ‘Minds eye’ - activity requiring visual information input e.g flying will constantly be using it.
- ‘Mental ear’ - constant use during verbal processing tasks
- They can allow you to multi-task e.g fly plane and talk to control. However only if one of these tasks is well learned, otherwise they compete for central executive
What are the potential consequences of high (cognitive) workload? (5)
- Attentional and task focusing
- Task shedding and reprioritization
- Implications for Situation awareness
- Increased use of decision short cuts and less scrutiny or review.
- Increased fatigue and chance of error
What are the 3 levels of situational awareness?
- Perceiving the situation
- Understanding the situation
- Projecting the situation
What is recognition primed decision making?
- Typical situations recognised from prior experience.
- decision maker simulates first option that comes to mind, and if it is acceptable carry it out.
- if not, simulate another option etc.
Describe the 3 stages of acute stress
- Alarm reaction - fight/flight, cortisol/adrenaline etc.
- Resistance - body attempts to repair any damage from stress allowing it to adapt to sustained/chronic stress e.g. extreme cold, personal worries. If over long period body will attempt to maintain constant arousal
- Exhaustion - short lived, affects part of body involved in resistance. If resistance/exhaustion phases prolonged get headaches/HTN etc
What 3 types of stressors does CAA mention?
- Environmental (physical)
- Psychological
- Organisational
What are the affects of the following vibration:
1. 1-4 Hz
2. 4-10 Hz
3. 8-12 Hz
4. 10-12 Hz
5. 30 - 40 Hz
- interference with breathing; neck pain
- chest and abdominal pain
- backache
- headache, eyestrain, throat pain, speech difficulty, muscle tension
- Interference with vision
What levels of noise have been shown to impact on performance?
> 80 dB - task performance may be impaired
> 90 dB - measurable impairment of task performance
What level of humidity is:
1. normal
2. causes discomfort
- 40-60%
- < 20%
What are the following in relation to stress?
- Omission
- Error
- Queuing
- Filtering
- Approximation
- Coning of attention
- Regression
- Escape
- Completely omitting a particular action
- Incorrect response to a given stimulus
- Sequentially delaying necessary actions in an inappropriate order of attention priority
- Rejection of certain tasks because of overload
- Making approximations in technique in an attempt to cope with all the tasks required in a short-term interval
- Attention scan closes in to a smaller field of awareness.
- Behaviour may regress to the earliest learned, such as operating a control
- Ultimate response to extreme levels of stress is to give up or freeze.
What are the following stress coping strategies outlined by the CAA?
1. Action coping
2. Cognitive coping
3. System directed coping
- individual takes some action to reduce the stress either by removing the problem or altering the situation.
- If situation can’t be changed. Rationalisation/detachment to change perception and limit impact.
- Stress management techniques - exercise, meditation, drugs, alcohol etc.
How much of your ‘sleep debt’ do you need to get with a catch up sleep?
Approx 1/3
What are the different times in the first 3 stages of sleep?
- Transition phase -10 mins
- 15 mins
- 15 mins
Describe the sleep cycles throughout the night
Stage 1/Transitional:
- 10 mins only.
- still some awareness.
- Hypnogogia.
- Microsleep (like at wheel of car)
Stage 2/Light sleep
- 15mins
- HR RR and temp DECREASE.
Stage 3 and 4 / Deep:
- 30 mins in duration
- Brain produces SLOW DELTA WAVES.
- Groggy (sleep inertia) if woken in this stage.
Stage 5/ REM sleep.
- Dreams
- Muscles relax.
- HR/RR speed up.
- Brainwaves speed up.
Cycle of stage 1-4 and REM repeats in 90 mins cycle with increasing time in REM and decreasing time in stage 4
Which phases are ‘slow wave’ sleep?
Stage 3 and 4
What is thought to be the function of:
1. Stage 1-4 sleep
2. REM sleep
- Body restoration
- Strengthening and organising memory
Where are circadian rhythms controlled?
Suprachiasmatic nucleus of the hypothalamus
How much does your body temperature change throughout the day and when is it highest + lowest?
- within 1 degree C
- Lowest 6am
- Highest 8pm
What is melatonin and how does it work?
Hormone secreted by the pineal gland with a rhythm linked to the light/dark cycle through the suprachiasmatic nucleus.
What medications do the CAA recommend to aid with sleep? (2)
- Temazepam
- Melatonin
What are the 2 personality factors Eysenck developed and which 3 others are added to create the ‘Big 5’?
- Neuroticism stable (emotional stability/ anxiety) (N)
- Introversion/extroversion continium (E)
- Openness to experience (O)
- Agreeableness (A)
- Conscientiousness (C)
OCEAN - gives score
In terms of culture - what do the following mean?
1. PDI
2. IDV
3. MAS
4. UA
5. LTO
6. IND
- Power Distance - acceptance of amount of power held by most powerful in society by those with the least
- Individualism vs collectivism
- Masculine vs feminism - some societies more masculine and some feminine in culture
- Uncertainty avoidance
- Long term orientation e.g China
- Indulgence vs restraint
What is ‘risky shift’?
- The tendency of groups to err on the side of either extremely high or low risk strategies
- individual doubts recede as others appear to agree + diffusion of responsibility occurs
What are the 3 leadership styles described by CAA?
- Autocratic - task orientated
- Democratic - inclusive, balance between task and relationship orientated
- Lasseiz-faire - may set the task but allow the group members to do what they want
What are the 4 decision making methods described in SATSE and put them in order of increasing cognitive effort and stress?
- RPD - recognition primed
- Rule based -SOPs etc
- Choice decisions - comparing options, analysing them and choosing best one
- Creative - basis of innovation but unlikely to be helpful when time-critical
What are the 3 components of situational awareness (SATSE)
- Gathering information
- Interpreting information
- Anticipating future states
How much of communication is:
1. words
2. tone
3. non-verbal
- 7%
- 38%
- 55%
Describe the 4 aspects of communication outline in SATSE
- Explicitness - clear, brief and standardised e.g SBAR
- Timing - wait for appropriate gap, not too late/early
- Assertiveness -
passive-assertive-aggressive - Active listening
What is:
1. Transformational
2. Transactional
leadership?
- Leader provides vision, promotes intelligence and treats employees individually
- Contingent rewards e.g salary and manages by exception (looks for deviations
What are the elements of the balance model of stress?
- Perception of ability to cope (resource) with demand (Stressor)
- mediators (personality, fitness etc) can increase/decrease these effects
What are the symptoms acute stress? (SATSE)
BEST
Behavioral
Emotional
Somatic
Thinking
What are the 5 parts of Critical Incident Stress Management (CISH) outline in SATSE?
- Pre-crisis prep”
training/setting expectations - Demobilisation and consultation: debrief after shift
- Defusing: assess, begin closure/triage
< 12 hours post event - Critical incident stress briefing: ‘cold debrief’
<10 days or 1 month if MI - Crisis intervention / family CISM/follow up: surveillance for signs/symptoms
Can occur anytime
When does alertness peak and trough in terms of circadian rhythm?
- Peak between around 4pm
- Trough 3-6am
What are good rota rules to protect against fatigue?
- Slow progression: days - lates - nights
- 11 hours rest between
- Max 5-7 days work
What are the 5 variables used in the fatigue and risk calculator index (UK HSE)
- Time of day
- Shift duration
- Rest periods
- Breaks
- Cumulative fatigue
Give 8 ways to help maintain situational awareness? (SATSE)
- Good briefing
- Fitness to work
- Minimising interruptions at critical moments
- Sterile cockpit
- Updating - comparing regularly mental model
- Self monitoring
- Speaking up/ shallow command gradient
- Time management - avoid ‘hurry up’ syndrome
What time period is:
1. Acute stress disorder?
2. PTSD?
- 2 days to 1 month
- > 1 month
What is ‘groupthink’?
Group suspending its rational judgement in order to maintain group cohesion e.g bay of pigs
What is the SHELL model?
Analyses interactions between humans (Liveware) and the systems they operate within to understand and potential errors
Describe the elements of the SHELL model of errors
S (Software):
Procedures, manuals, guidelines etc.
H (Hardware):
Equipment, tools and physical environment of the workplace.
E (Environment):
Climate, noise etc. and organisational culture.
L (Liveware):
Represents the human element, encompassing both individual and group aspects such as skills, knowledge, teamwork, communication, and leadership.
How long does it take to recover following sleep deprivation?
2 nights
