Environmental topic 4 - ergonomics (human factors)

Question 1

Background - Cognitive load theory

Answer 1

• capacity of humans to process incoming stimuli is limited
• information overload occurs when capacity is exceeded, claiming our attention
• most attention is given to stimuli that are intense, unpredictable and may require some adaptive response

Question 2

Background - working memory model

Answer 2

Baddeley and Hitch-memory has several sub-systems that process different types of incoming information, as shown by the diagram
Baddeley - participants had more difficulty completing two visual tasks from cognitive overload

Question 3

Background - Mayo ‘Hawthorne studies’

Answer 3

aim: the impacts of the physical environment on the productivity levels of workers
- one aspect was light - experimental group - lights constantly varied, control stayed the same
Results:
increased productivity from experimental, however could have been the observation rather than the light

Question 4

Background - observation affects

Answer 4

social facilitation - increased level of effort as a result of the real, imagined and implied presence of others
Co-action effect - an increase in performance from others completing the task
audience effect - dominance response to occur, from individuals being influenced by others
social inhibition - decreased performance in the presence of others occurs for difficult or novel tasks

Question 5

Key research - Drews and Doig - aim and sample

Answer 5

aim: benefits of using graphical data instead of numerical to see trends in data
- improve CVS would decrease mental demand from nurses monitoring patients
included two elements:
1. current state object - current state of patient’s vital signs
2. shapes and colours increase the speed of information processed
sample: 42 registered nurses all had critical care training and a minimum of one years experience in the ICU.
- 69% female, mean age of 44

Question 6

Key research - Drews and Doig - procedure

Answer 6

• independent measures - assigned to CVS display or control group
• lab experiment for standardised training
• received specific patient information for each scenario
• 4 scenarios: early sepsis, septic shock, pulmonary embolism and stable state
• 5 mins to complete evaluation of scenario, once completed given 7 point likert scale - clinical desirability of the CVS and realism of the scenario. Then NASA - TLX questionnaire about workload

Question 7

Key research - D&D - results and conclusions

Answer 7

Results:
- speed of response - 30% increase using CVS
- accuracy of response - more frequently able to identify condition, than control
- nurses felt less stressed than control
Conclusion:
- showing trend data will allow more nurses to make accurate diagnoses and condition of patients, reducing cognitive load

Question 8

Key research - D&D - evaluations

Answer 8

Strengths:
- lab experiment - standardised
- high internal validity - from time training
- high population validity
- scenarios were realistic - same scenario higher internal and external reliability from replicability
Weaknesses:
- low ecological validity - lab doesn’t depict hospital environment, however ethically sound
- the gynocentric majority, however, realistic and expected sample of nurses
- use of self - report, socially desirable ratings of themselves possibly
- inconsistency from independent measures
- ethnocentric - western, likely do one job at a time (monochronic), than eastern (polychronic)
- only looking at ICU and other units may utilise findings in different ways

Question 9

Application - workplace design based on ergonomic research

Answer 9

Closed office spaces - reduce the cognitive load from minimalism and verbal reduction
- use of a collaboration workplace, higher productivity and gives more privacy and comfort from the audience effect
Lusk:
- found significant health benefits from reduced noise including stress and blood pressure
Danielson:
- found fewer female staff absences - personalisation of space and reduction of cognitive overload