E1 Human Factors Design

E.1.1 Identify the objectives of human factors design.
Human factors (ergonomics) is the application of scientific information concerning the relationship of human beings to the design of objects, systems and environments.

Types of ergonomics:
Physical - Physical activity regarding anthropometric characteristics within our environment (school, work, transport), includes lights, sound, heating etc.
Relates to: workplace layout, health and safety, repetitive movements
Cognitive - Concerns mental processes like perception, memory, reasoning, motor responses.
Relates to: mental workload, decision making, human-computer interactions.
Organizational - Structures within a workplace, like
Relates to: communication systems, shift patterns, participatory design
Project work - Ergonomists can become specialists
Relates to: How people interact with their environment, automobile design, safety of underground systems etc.

Objectives:
Effectiveness - Increasing the effectiveness of the product or process; often relating to the completeness and accuracy of processes.
(e.g. designing a very technologically advanced product, but its interface is not user-friendly)
Efficiency - Increase the speed of the process and reduce effort. Lower effort and higher speed means greater efficiency.
(e.g. a shopping cart that travels faster with a smaller force applied)
Engagement - Improve user experience (pleasantness and satisfaction)
Error Tolerance -

E.1.2 Describe why visibility is an important consideration in human factors design.
Controls should be visible, and it should be obvious how they work. They should convey the correct message. 
e.g. doors that need to be pushed, the designers must provide signals to indicate where to push, like a push plate.

E.1.3 Describe why feedback is an important consideration in human factors design.
Feedback is the provision of information.
e.g. an audible tone to the user, a result of an action, the tone on a telephone, touch pad or a click on the computer provides feedback to indicate that our key has been pressed. The time icon on a computer screen tells the user that an action has been under taken.

E.1.4 Describe why mapping is an important consideration in human factors design.
Mapping relates to the correspondence between the layout of the controls and their required action.
e.g. the layout of the controls on a cooker hob can take advantage of physical analogies and cultural standards to facilitate a user's understanding of how it works. The location of controls must bear a logical relationship to the position of the relevant information or to the effect of those controls.

E.1.5 Describe why affordance is an important consideration in human factors design.
The property of an object that indicates how it can be used.
Buttons/push plates afford pushing. Knobs afford turning/ twisting. A blinking red light/ buzzer suggests a problem and demands attention. A chair's size, curvature and position suggests sitting on it.

E.1.6 Describe why constraints are an important consideration in human factors design.
Constraints: limits the way a product can be used.
e.g. the three-pin plug or USB ensures that they are inserted the correct way, hence reduces the possibility of a user making errors.

E.1.7 Explain why consumers misuse many products due to inappropriate human factors considerations in their design.
It is not always obvious from looking at products how they should be used.
Visibility - Inappropriate visibility e.g. wrongly labelled doors, users may push a 'pull' door and break it.
Feedback - Inappropriate/lack of feedback e.g. if a button or app is clicked but there is no response, the user may repeat the action hoping for a response. This repeated process may cause the computer to crash
Mapping - Inappropriate mapping or using unconventional methods of designing e.g. the controls in a car
Affordance - Inappropriately placed instructional objects may cause confusion e.g. push plates on a "pull" door
Constraints - Unclear constraints e.g. sometimes the USB is inserted in the reversed orientation because of its symmetrical outer shell, causing unnecessary misuse.

E.1.8 Explain why the aims of human factors may conflict with other design aims.
There is always a compromise between different design aims. Cost, form, or function may be more important aims to achieve in a specific design context.

E.1.9 Explain that the ergonomic data required in systems design depends on the role of people in that system.
Reduced system efficiency and failures that occur early in the life cycle are frequently caused by poor human factors design.
e.g. unfamiliar symbols or pictograms