Ergonomics

Question 1

What is Ergonomics ?

Answer 1

• Designing equipment to fit the human body and its cognitive abilities
• Ensuring the machinery is designed to fit in with the way people think.

Question 2

What is the Multi store model of memory ?

Answer 2

• Memory is made up of a series of stores in a linear fashion and information flows through the system.
• Info detected by the senses and enters sensory memory.
• If attended to it goes to short term memory, if not it is lost.
• Info goes into long-term memory through rehearsal.
• If this does not happen, it is forgotten through displacement or decay.

Question 3

What is the Working Memory model ?

Answer 3

• Is short-term memory

- Central executive consists of the phonological loop and the visuo-spatial sketch pad.

Question 4

What is the Visuo-spatial sketch pad ?

Answer 4

• Stores and processes information in spatial form

- Important in navigation.

Question 5

What is the Phonological loop ?

Answer 5

• Deals with spoken and written material.

- Perception of speech and production of speech

Question 6

How can short term memory be limited by the task ?

Answer 6

• Use of the sketchpad is interfered with by visual tasks, but not by verbal tasks.
• The phonological loop is interfered with by verbal tasks but not by visual tasks.
• If info is presented in different forms, you can hold more in your working memory, than if its in the same form

Question 7

What is Cognitive Overload ?

Answer 7

• There is a limit to the amount of stimuli that people can handle at any one time.
• Limited capacity to process stimuli
• Leads to Info overload, focus on the harder task
• Give most attention to intense stimuli or ones that require an adaptive response
• Capacity for attention can be temporarily depleted by prolonged demands on it that leave it overloaded.

Question 8

How should work tasks be designed ?

Answer 8

• Around the theory we have a limited working memory and a comparatively unlimited long term memory.
• Working memory is crucial when performing a new or highly-complex task.

Question 9

What is The Hawthorne Effect ?

Answer 9

• People to try harder and perform better when they are participants in an experiment.
• Individuals may change their behaviour due to the attention they are receiving from researchers
• Rather than because of any manipulation of the independent variable.

Question 10

What is Social facilitation ?

Answer 10

• Performance is altered due to the presence of other people
• An audience can have a positive or negative effect on performance.

Question 11

What theories support social facilitation ?

Answer 11

• Norman Triplett (1898) observed cyclists performed better when they were racing against others rather than against the clock. The presence of others doing the same activity enhanced performance.
• Later research showed just an audience, rather than competitors increased performance. But only if people felt the audience was evaluating them.
• Sometimes people perform worse on tasks when there are other people watching.
• Triplett (1898) saw children given a task to operate a small piece of machinery, either in the presence of others, or alone.
• Some performed better alone, others with people watching.

Question 12

What was Zajonc Social facilitation theory ?

Answer 12

• Zajonc (1965) proposed being in the presence of others causes arousal, leading to an increase in performance
• Used cockroaches in a maze and found that in general performance on simple tasks was enhanced by an audience whilst performance on harder tasks was decreased by an audience.
• They were 10s faster with an audience when they had to run in a straight line.

Question 13

What was the Aim of Drews and Doig’s study ?

Answer 13

• To develop an ICU display that presents vital signs trend information to support the detection and identification of acute physiological changes in patient state.
• To test whether improved ICU monitoring display reduces the cognitive load on the staff

Question 14

What was the method of Drews and Doig’s study ?

Answer 14

• 4 scenarios
• Had 5 mins to complete each scenario – early sepsis, septic shock, pulmonary embolism and stable state.
• Told to verbally evaluate the patient’s physiological status, interpret the data and recommend appropriate interventions.
• After the scenarios the nurses were asked to complete questionaries on the desirability of the new CVS display and the realism of the scenarios.
• Most important data was the speed of the response and the accuracy of the interpretation.
• If no assessment was given within 300s that was determined to be the response time.

Question 15

What was the sample in Drews and Doig’s study ?

Answer 15

• 42 registered nurses – all had critical care training and a minimum of one year’s ICU experience.
• 21 in each condition – experimental group and control.
• The experimental group used the new display
• Control used a simplified version without the trend data- they had to press a key to access it.

Question 16

What were the results of Drews and Doig’s study ?

Answer 16

• The nurses were able to respond significantly faster to the new CVS display. There was a 30% improvement in response times.
• CVS condition nurses correctly identified the patient’s condition more frequently than controls.

Question 17

What was concluded from Drews and Doig’s study ?

Answer 17

• The CVS display produced faster response times – in two out of the three abnormal scenarios, nurses were 43% faster on average.
• Accuracy also improved by a third or more.
• Strongly suggests a display integrating current and trend information can improve assessment in some clinical conditions.
• Nurses only infrequently accessed the extra information in the control condition – possibly due to extra effort and suggests display designs should incorporate more on the main screen.
• better display design could reduce cognitive load for nurses and improve patient care.

Question 18

What strategies to reduce cognitive load ?

Answer 18

• Reduce the amount of unnecessary repetition load put on the working memory.
• Use visual and auditory techniques to increase short term memory capacity.
• Remove unnecessary visual elements because these need to be processed and increase cognitive load.
• Use chunking to reduce the number of things that have to be attended to at once.
• Reduce choices needed to make a decision – because time to decide increases with the number of choices available.
• Pairing staff up for simpler tasks – social facilitation
• Have managers watching and evaluating staff
• Colour coding shelves and areas in the warehouse where the things for that shelf are kept, reducing cognitive load.