PSYC 2800:An Introduction to Human Factors Engineering Exam Review:
1) Describe the key work environment factors associated with the “vigilance
- Definition: “deterioration in the ability to remain vigilant for critical signals
with time, as indicated by a decline in the rate of the correct detection of
- Vigilance or “concentration” is defined as the ability to maintain concentrated
attention over prolonged periods of time.
- During this time, an individual attempts to detect the appearance of a
particular target stimulus. The individual watches for a signal stimulus that
may occur at an unknown time.
- Vigilance is used today due to the increased interaction of people with
machines for applications involving monitoring and detection of rare events
and weak signals.
- Can be used in: air traffic control, inspection and quality control, automated
navigation, military and border surveillance and lifeguarding.
- Most commonly associated with monitoring to detect a weak target signal
- Detection performance loss is less likely to occur in cases where the target
signal exhibits a high saliency. Ex: a radar operator would be unlikely to miss
a target at the end of a watch if it were a large bright flashing signal, but might
miss a small dim signal.
- Is significant within the first 15 min of attention.
- Research indicates that vigilance is hard work requiring the allocation of
significant cognitive resources and includes significant levels of stress.
- Was initiated by Norman Mackworth during WWII and the “clock test”
- Factors: discrimination type and event rate, measuring mental workload
during vigilance tasks, stress, individual differences in performance, aging
lack of habituation.
- Reducing vigilance decrement: practise, performance feedback amphetamines
and rest are believed to moderate temporal performance decline without
- Vigilance decrement was originally thought to be caused by a decline in
arousal brought about by the under stimulating nature of vigilance tasks.
According to that view, the repetitious and monotonous aspects of vigilance
tasks suppress activity in brain systems, making it difficult to maintain
- Vigilance tasks have traditionally been considered to be under stimulating and
mentally undemanding. Research has proven that conventional wisdom wrong
rather than being simple work assignments as originally believed vigilance
tasks are exacting, capacity-draining assignments that are resource
demanding. They are also associated with a considerable level of subjective
workload and stress. These aspects need to be considered in the design of
work environments involving vigilance functions and in the evaluation of
those who carry such functions. It may also be critical to design tasks to afford
engagement, autonomy and challenge. 2) What are the three things one should remember when designing warning labels?
- People vary in their proclivity for risk taking
- Descriptive word that conveys hazard seriousness
- Description of nature of hazard
- Description of consequences of the hazard
- Description of action needed to avoid the hazard
a) To determine which hazardous materials intended for use in the workplace are
- Ex: compressed gas, flammable and combustible material, ect.
- Supplier should test material and classify it under classes A,B,C,D,E, or F.
b) To label all controlled products as a condition of sale or importation
- Name of the product
- Same of the supplier
- Reference to a material safety data sheet
- Hazard symbols
- Risk phrases
- Precautionary measures
- First aid measures
c) To provide material safety data sheets for controlled products as a condition of
sale or importation
- Is a technical document that summarizes the health and safety information
available about a controlled product
- It supplements the warning information on the label
4) List the characteristics of the social environment associated with workplace accidents
and provide examples.
- Social environmental factors: workload, hours, environment, safety culture,
provision of quality supervision, provision of occupational health and safety
training, socially structure, and influence individual worker attitudes and
behaviours in workplace injury.
- Safety culture- a product of social leaning and socialization about safety in
work practices. Consists of shared perceptions, thoughts and beliefs regarding
safety and safe work practices. Safety culture refers to the way in which safety
is managed in the workplace and often reflects the attitudes and perceptions
that employees and employers collectively share in relation to safety. Without
a collective safety culture, workers are unaware of risks associated with work
environments and work practices. This exposes workers to higher rates of
workplace injuries and fatalities.
- a lack of safety culture in the workplace
- a lack of supervision, is associated as a contributing social factor in workplace
injuries and fatalities.
- Lack of quality health and safety training
- Insufficient training - Insufficient resources
- Low social cohesion – “new on the job”, not familiar with how workers
communicate within the new work environment.
- Perceived work overload
6) List personnel factors associated with workplace accidents.
- “Part of the job” mentality – suggests some youth perceive minor injuries as “part
of the job” because they happen often and are not severe.
- Intimidation – younger workers might feel powerless
- Newness- being a novice on the job and unfamiliar with the work or hazards
- Physical development factors- postures, repetitive motions and ergonomic
mistakes between worker and machines/equipment resulting in strain or injury
- Cognitive development- may lack development in decision-making decisions
- Risk taking
- Age, gender and personality.
8) Statistical significance- Definition: A mathematical technique to measure whether the
results of a study are likely to be true. Statistical significance is calculated as the probability that an
effect observed in a research study is occurring because of chance. Statistical significance is usually
expressed as a Pvalue. The smaller the Pvalue, the less likely it is that the results are due to chance (and
more likely that the results are true). Researchers generally believe the results are probably true if the
statistical significance is a Pvalue less than 0.05 (p