Alt 1: Human Factors and Human Error

Question 1

Time and Motion studies:

Answer 1

Time: How fast could each task (and sub-task) be
performed?
Motion: What were the fewest motions required for each task (and sub-task)?

Question 2

To design (or engineer) systems while taking psychological and physical factors into account

Answer 2

Human Factors

Question 3

Goals of Human Factors

Answer 3

1. Enhance performance (productivity)
2. Increase user satisfaction (usability, comfort)
3. Increase safety (error reduction)

Question 4

What is a socio-technical system?

Answer 4

System that includes both social and technical elements:
Social: Includes individual and team factors
Technological: Includes equipment, machines, tools
and technology

Question 5

How might we enhance performance?

Answer 5

Removing unnecessary steps from a task
Creating a more efficient work-space layout
Selecting personnel with greater aptitude for a task

Question 6

How might we increase user satisfaction?

Answer 6

Building a more intuitive interface
Maintaining comfortable temperature, light, noise levels
Minimising fatigue

Question 7

How might we increase safety?

Answer 7

Error reduction:
- Ensuring all essential information is provided to user
- Ensuring any error is visible to user
- Ensuring any error can be recovered from or
‘reversed’
Increasing safety:
- Building defences against frequent forms of error
- Reducing the occurrence of error through training
- Managing task design to reduce workload
- System monitoring

Question 8

A generic term to encompass all those occasions in which a sequence of mental or physical activities fails to achieve its intended outcome, and when these failures cannot be attributed to the intervention of some chance agency

Answer 8

Human Error

Question 9

Why errors occur?

Answer 9

Reason #1: We don’t like to expend too much effort on a task

Reason #2: Human fallibility

Question 10

Rasmussen (1986) highlighted three different approaches to task performance:

Answer 10

1. Skill-based
2. Rule-based
3. Knowledgebased

Question 11

Skill-based behaviour:

Answer 11

The lowest level of the cognitive processing hierarchy
Little to no conscious attention (bottom-up processing)
Relatively automatic, routine behaviours

Question 12

Rule-based behaviour:

Answer 12

The middle level of the cognitive processing hierarchy
A mix of automatic/conscious processing
Used to solve ‘trained for’ problems with ‘if-then’ type associations

Question 13

Knowledge-based behaviour:

Answer 13

Highest level of cognitive processing hierarchy
Conscious, only used if skill and rule behaviour inadequate
Effortful processing
We apply this to novel situations

Question 14

Types of error

Answer 14

Mistakes: Errors of Perception & Interpretation
Lapses: Failure of storage
Slips: Incorrect execution

Question 15

Error in:
Perceptual Encoding
Assessing a task/situation

Answer 15

Mistakes: Errors of Perception & Interpretation

Question 16

Error in:
Central Processing
Planning the action/cognition

Answer 16

Lapses: Failure of storage

Question 17

Error in:
Responding
Executing the action/cognition

Answer 17

Slips: Incorrect execution

Question 18

Contextual factors that might contribute to error:

Answer 18

1. Work environment
2. Equipment/interface design
3. Organisational/social factors

Question 19

Barriers

Answer 19

Barriers are designed to prevent errors or hazardous events from occurring