Human Factors & Ergonomics Flashcards
Anthropometric data:
Structural Data
The measurements when body is in a fixed position
I.E: static such as height, joint to joint and physical capacity
Anthropometric data:
Dynamic data
The measurements that relate a range or reach of various types of body movements.
I.E: reach, grip, strength and reaction times
Percentile Range
That proportion of a population with a dimension at or less than a given value.
When considering percentile ranges the design context factors in as well.
If comfort or safety are important than a range of percentiles must be considered.
For example motorcycle helmets need to fit snugly in order to function properly in protecting the head.
Psychology Factors
Psychological factors include, smell, light, sound, taste, texture and temperature.
These are a significant part of ergonomics and human efficiency and safety can be affected by these factors.
Nominal
This scale only classifies objects into discrete categories, for example, food groups. Nominal means ”by name” and labels are used for the categories of objects.
Nominal scales are very weak, as they do not tell you anything more than that one object is different from another.
Ordinal
As with nominal scales, the labels used in ordinal scales can be words, symbols, letters or numerals.
When numerals are used, they only indicate sequence or order, for example, ranking someone by placing them in a competition as “third” rather than by a score—they may have come third with 50% right or with 75%.
Interval
An interval scale is a more powerful scale, as the intervals or difference between the points or units are of an equal size.
For example, in a temperature scale. Measurements using an interval scale can be subjected to numerical or quantitative analysis.
Ratio:
The difference between a ratio scale and an interval scale is that the zero point on an interval scale is some arbitrarily agreed value, whereas on a ratio scale it is a true zero.
For example, 0°C has been defined arbitrarily as the freezing temperature of water, whereas 0 grams is a true zero, that is, no mass.
A breakdown in the human information processing system
age – too young and maybe have not learnt the skills.
strength – too weak to carry out the task
skills.
health -when mental or physical health is comprised which may lead to not carrying out the necessary tasks.
Effect of environmental factors
Alertness
Temperature: too warm and you get sleepy and less alert.
Sound: too loud which can be distracting or even cause harm, high pitched or repetitive also become distracting.
Lighting: too dim hard to see things need to get close or strains eyes.
Air quality: excess dust or other pollutants could cause people to find it hard to breathe.
Smell – bad smells will draw ones attention away.
Physiological factor data
Types of physiological factor data available to designers
Bodily tolerances such as fatigue and comfort.
Muscle strength in different body positions
endurance in different body positions
Tolerance to extremes of temperature
Size
Eye/Hand coordination
Importance of Biomechanics
The importance of biomechanics to the design of different products considering muscle strength, age of user, user interface (surface texture, handle size, etc) and torque.
