Human Characteristics Overview

Human Characteristics

• Human Characteristics can be categorized into four main groups: Psychological, Physiological and Anatomical, Group factors, and Individual Differences.
• Psychological factors include:
  • Mental workload
  • Stress
  • Fatigue
  • Learning and memory
  • Motivation
  • Attention
• Physiological and Anatomical factors include:
  • Physical capacity
  • Strength
  • Endurance
  • Sensory capabilities
• Group factors include:
  • Team dynamics
  • Communication
  • Social interaction
• Individual differences include:
  • Age
  • Gender
  • Experience
  • Culture
  • Cognitive abilities
  • Personality
• Psychophysiological state variables refer to psychological states that affect the physical body. Examples include:
  • Heart rate
  • Blood pressure
  • Body temperature
  • Pupil dilation
  • Muscle tension
• Task-related factors are environmental factors that influence an individual’s ability to perform a task. Some examples of task-related factors include:
  • Task complexity
  • Task duration
  • Working hours
  • Working conditions
  • Work environment
  • Work organization
  • Ergonomics

The Physical Environment

• The physical environment can influence human performance and well-being.
• Environmental factors that influence performance include:
  • Illumination: Adequate lighting is essential for visual tasks
  • Noise: Excess noise can be distracting and stressful.
  • Vibration: Vibration can cause discomfort and health issues.
  • Climate: Temperature, humidity, and air quality can affect comfort and productivity.
  • Altitude, depth, and space: These factors can impact the physical capabilities of an organism and necessitate specialized designs. The body is more sensitive to external pressures at these extremes.
  • Other environmental issues include:
  • Radiation - Electromagnetic radiation (radio waves, microwaves, visible light, ultraviolet radiation, X-rays, and gamma rays) can impact human health.
  • Pollution - Gases, liquids, and solid particles in the air or water may be harmful to human health.
  • Chemicals - Harmful substances can contaminate the air, water, and soil. Workers must be protected from potential exposure to hazardous substances.
  • Heat stress - The human body's ability to regulate its temperature is affected by high ambient temperatures.
  • Cold stress: The body's ability to maintain its core temperature is affected by low temperatures.

Socio-Economic Factors

• Trade Unions: Trade unions advocate for their members' rights and improve their working conditions.
• Employment, job security, and job sharing: These factors affect workers' well-being and their ability to perform at their best.
• Productivity: Socio-economic factors such as wages, working conditions, and job security can impact productivity.
• Women in the workplace: Women face unique challenges in the workplace, including gender bias, pay inequity, and limited access to leadership positions.
• Organizational design: The design of an organization can impact worker productivity and morale. An organization’s design can foster collaboration and communication, or it can create silos and inefficiencies.
• Law: Legislation can influence the work environment. Examples include laws regarding workplace safety, discrimination, and employee rights.

Work Design and Organization

• Designing a system, particularly a workplace, requires taking into account human characteristics.
• Work design and organization impact human well-being and productivity.
• Total system design considers the entire work system, encompassing the interaction between all components.
• Hours of work: Excessive hours can lead to fatigue, stress, and health problems.
• Job attitudes and satisfaction: These influence job performance and overall well-being.
• Job design: Job design influences job satisfaction and performance. Some factors involved in designing jobs include complexity, autonomy, meaningfulness, control, feedback, and social interaction.
• Payment systems: The system for paying workers impacts their motivation.
• Technological and ergonomic change: Workplace technology can impact human performance and well-being.

Ergonomics

• Physical ergonomics focuses on the interaction between the human body and its environment.
• Cognitive ergonomics focuses on the human brain and how it processes information.
• Physical ergonomics concerns itself with physical exertion and physical limitations.

Anthropometry and Work Posture

• Anthropometry is an important consideration in design.
• Human variability refers to the differences in body dimensions among people.
• Anthropometric variables are used in the design of workspace, equipment, and tools. They are used to ensure a comfortable fit for most users.
• Accommodation of disability is an important ergonomic consideration. Tools and workplaces must consider the needs of people with various disabilities.

The Information Theory

• The Information Theory is one of the foundational theories in Cognitive Ergonomics.
• The Information Theory considers the complexity of information processing during daily life and the limitations of the human mind.

Human Information Processing

• Sensory System: The five senses receive information from the environment.
• Perception: Perception is the process of interpreting sensory information.
• Memory: Memory is the storing and retrieving of information.
• Response Selection and Execution: This process involves choosing and carrying out an action based on perception, memory, and other factors.

The Human Sensory System

• Sensation is the process of receiving information through the senses.
• Exteroceptors are sensory organs that receive stimuli from the external environment.
• Vision is one of the most important sensory processes, as the eyes can gather up to 80% of all information processed by the body.
• Situational awareness is the ability to understand the context of a situation and the factors that are influencing it.
• Concentration is focusing attention on a specific activity or task.

Perceiving Forms, Patterns, and Objects

• Reversible Figure: These figures demonstrate how the same visual input can result in radically different perceptions. This is why people's interpretations of the world are subjective.
• Gestalt Principles: These principles explain how the visual system organizes a scene into discrete forms.
  • Figure and ground: The tendency to perceive objects as existing on a background.
  • Proximity: The tendency to perceive objects close to each other as part of the same group.
  • Similarity: The tendency to perceive objects with similar characteristics as belonging to the same group.
  • Continuity: The tendency to perceive a continuous pattern rather than a broken-up pattern.
  • Simplicity: The tendency to group elements that combine to form a 'good' figure (the simplest possible figure).
  • Common Fate: The tendency to group together things that move together.
  • Closure: The tendency to create a sense of closure or completeness even when there are gaps.

Perceptual Constancies

• Perceptual constancy is the tendency to experience a stable perception in the face of changing sensory input.

Misleading Cues: Optical Illusions

• An optical illusion is a discrepancy between the appearance of a visual stimulus and its physical reality.
• Attention is an important component of human information processing.

Attention

• Attention is the mental process of concentrating on specific stimuli while ignoring others.
• Attention Resources refers to the limited ability of the human mind to attend to multiple stimuli.

Display Information

• Display Information is any information presented to a user through a visual display.
• Quantitative Information is information that can be measured, counted, and expressed in numbers.
• Qualitative Information is information that is based on descriptions rather than measurements.
• Status Information reflects the condition or status of a system at a particular moment in time.
• Warning and Signal Information is used to indicate emergency or unsafe conditions.
• Representational Information is a pictorial or graphic representation of objects.
• Alphanumerical and Symbolic Information includes verbal, numerical, and coded information.
• Identification Information is used to identify a static condition or object.
• Time-phased Information is information that is distributed over time.