Ergonomics Flashcards
What are ergonomics?
Design of architecture, rooms, tools, furniture or gadgets etc to ensure a user doesn’t experience:
Physical discomfort eg back pain, eye strain
Cognitive discomfort eg overloading attention
Key research
Drews and Doig
Outline of Drews and Doig’s experiment
Design and evaluate a new screen in intensive care units displaying patient’s vitals to help nurses quickly and accurately detect a patient’s condition compared to traditional ICU screens
Traditional ICU displays in Drews and Doig’s study
Information for patients immediate blood pressure, heart rate and oxygenation of blood is in numerical display
To access data showing trend of this info, a single key press is required
New CVS display design in Drews and Doig’s study
Graphical displays of vitals: one showing trend of vitals over 8 hours
and one known as current state object (CSO) which is another graph display of maximum/minimum vital readings over past 1 hour
Numerical displays
‘Current state object’ in Drews and Doig’s study
Grey rectangle’s boundaries show normal highest/lowest HR + BP
Solid White rectangle to show max/min patients vitals over 1 hour
Coloured (based on oxygen saturation) rectangle to show current vital reading
Does the new CVS display require pressing any key?
No all information is presented on one screen: graphical trend etc
Sample in Drews and Doig’s study
42 nurses with min 1 year working in ICU
More women than men
Large age range
Sample in Drews and Doig’s study
42 nurses with min 1 year working in ICU
More women than men
Large age range
Main procedure of Drews and Doig
Present patients with 4 fake scenarios of patients vitals eg septic shock
Half presented via traditional display, half on new display
Have 5 mins to verbalise assessment of patient data and make decision
Main procedure of Drews and Doig
Present patients with 4 fake scenarios of patients vitals eg septic shock
Half presented via traditional display, half on new display
Have 5 mins to verbalise assessment of patient data and make decision
IV of Drews and Doig?
Data displayed on traditional ICU display
Or on new display
Dependent variable of Drews and Doig
Time taken for nurse to verbalise assessment
Accuracy of nurse’s assessment
Nurse’s mental demand when completing task
How did we measure the nurse’s mental demand required when completing the tasks in Drews and Doig’s study?
Give a survey to the nurses after completing the task
Results in Drews and Doig for identifying septic shock?
48% quicker response rate when given new display compared to trad display
1/3 more accurate using new display relative to trad display
Results in Drews and Doig for mental demand of nurses?
Significantly lower mental demand using graphical, new display relative to trad display
Conclusion of Drews and Doig?
Presenting nurses with patients vitals in graphical trend vs numerical data leads to quicker and more accurate diagnosis
Additional studies
Miller - short term memory and chunking
The Hawthorne studies
Higuer-Trujillo - colour of class walls
Brown and Poulton - secondary task performance
Miller’s theory on short term memory
Previous research said STM exists as the first stage in storing long term memory
Miller days people can hold from 5 to 9 pieces of info in STM
Miller’s theory on chunking
If we chunk info into units and related to something meaningful to us we can remember large amounts of info in the 7 pieces
Who did the Hawthorne studies?
Mayo NOT HAWTHORNE
Hawthorne studies aim
Investigate impact of physical environment on productivity of workers at Hawthorne factory plant of electric company that makes lightbulbs
By changing light level
Results of Hawthorne studies
Any change in light levels lead to increased productivity of factory workers because they knew they were being observed
Hawthorne effect
When people change their behaviour from their naturalistic behaviour because they are aware they are being observed
Higuera-Trujillo aim
Investigate the affect of colour of classroom walls on memory and attention using VR classroom
Higuera-Trujillo sample
80 Spanish Uni students half male, half female
Higuera-Trujillo procedure
Have Ps wear VR headset in class where they complete a memory and cognitive task, manipulating colour of walls each time to see which colour had best performance
Best colour walls, performance wise in Higuera-Trujillo
Purple
What is cognitive overload theory?
The idea that there is a limit on the number of items in the environment that can be paid attention to, this creates cognitive demand
How can we measure cognitive overload?
Secondary task performance, eg how well someone performs on a secondary task while completing a primary task
We can measure the spare capacity someone has left over in terms of how well they do on the primary task
Who used secondary task performance to measure cognitive overload?
Brown and Poulton
Brown and Poulton’s primary task
Have participants drive a car in a crowded car park with many cognitive outputs vs one with few (quiet residential area) this is the primary task of driving
Brown and Poulton secondary task
Listen to tape and identify the numbers moving from one sequence to next
What did brown and Poulton find out?
Worse performance on secondary task in the crowded shopping centre as there were more cognitive inputs so less mental capacity left over for the secondary task
Why do we learn about cognitive overload in terms of ergonomics?
Design of products/rooms should focus on not overloading user with cognitive inputs: too much too pay attention to
Why do we learn about memory in terms of ergonomics?
Having better short term memory storage means less mental demand thus less cognitive overload when experiencing the workplace
