different data scales
Ordinal Data Scale –> deals with the order or position of items, difference between each one is unknown, measures of non-numeric concepts, qualitative data
Nominal Data Scale –> “by name”, used in classification or division of objects into groups, doesn’t provide measurements, qualitative data
Interval Data Scale –> data organized into divisions or intervals of equal size, there is no zero, quantitative data (e.g. thermometer)
Ratio Data Scale –> allows to compare differences between numbers, no negative numbers, quantitative data (e.g. weight scales)
Biomechanics
= the research and analysis of how the human body works (operation of our tendons, muscles, joints, etc.)
- measures the amount of force put on our muscles and joints when working in different positions
Factors affecting muscle strength: gender, age, physical disability
4 key criteria for biomechanics
Force –> can cause muscle tenseness
Repetition –> can lead to musculoskeletal disorder
Duration –> continuous muscular effort
Posture –> can lead to discomfort and loss of attention
percentiles and percentile ranges
percentile => used to show whether the measurements given relates to the “average” person or someone who is above or below average
aims of human factors
- reduce stress and fatigue
- increase safety
- increase ease of use
- enhance operational comfort
- improve system performance
egonomics
application of scientific info concerning the relationship of human and the design
physical ergonomics
- posture
- repetitive stress & movement
- musculoskeletal disorders
- occupational safety and health
cognitive ergonomics
= mental processes
- perception
- memory
- reasoning
- motor response
–> these affect interactions between humans and other elements of the system
organizational ergonomics
- communication & teamwork
- work hours (shift work)
- resource & quality management
anthropometric data
measurements relative to design regarding the size and shape of the human body (quantitative measurements)
static and dynamic data
static/structural data = measurements taken of the human body while in a fixed or non-active position –> much easier to gather
dynamic/functional data = measurements of the human body taken during physical activities –> measuring how our bodies work and move (flexibility, muscle strength, reaction times, grip strength, range of motion) –> harder to gather but more useful data
tools to collect anthropometric data
- sliding and spreading calipers
- cloth tape
- sitting height meter
- stadiometer
human factors definition
the combination of egonomics and anthropometrics to make interactions between the user and product more efficient and comfortable
clearance and reach
clearance = distance between two objects –> 95th percentile is used
reach = a range that a person can stretch to touch or grab an object from a specific position
- used in the work envelope
range of sizes and adjustability
adjustability = available in different sizes or with adjustability built-in to be fit for a wider audience
- adjustability to be available for a range of sizes
ergonome and manikin
ergonome = 2D scaled physical anthropometric model based on a specific percentile human form –> to consider the relationship between the size of an object and people
manikin = an anatomical 3D model of the human body –> useful for assessing the relationship of body parts
methods to collect psychological data
- observation
- surveys & interviews
- case studies
psychological factors
relates to the 5 senses
- smell
- light
- sound
- taste
- texture
- temperature
human information processing systems
input –> sensory processes –> central processes –> motor processes –> output
how to maximise workplace performance
- management: policies
- physical environment: noise, temp, lighting
- equipment design: warnings, visibility, controls
- social and psychological environment: morale
- the worker: personal ability, alertness, age, fatigue
human error
slips = result from automatic behavior
mistakes = conscious deliberations
physiological factors
bodily tolerances such as comfort and fatigue
- how physical attributes affect the design
- these factors are used to optimise user safety, health, comfort, and performance
