Human-Computer Interaction: Human Factors

Human-Computer Interaction: Human Factors A comprehensive exploration of human factors and capabilities that influence human-computer interaction design. Learning Outcomes: Ability to explain human fa...

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Human-Computer Interaction: Human Factors

A comprehensive exploration of human factors and capabilities that influence human-computer interaction design.

Learning Outcomes: Ability to explain human factors in HCI (Human-Computer Interaction).

Chapter I: Human Factors

Definition of Human

According to various sources, humans are rational beings capable of mastering other creatures through their intellectual abilities.

Chapter II: Human Capabilities

Humans have several key capabilities in interaction, which include:

  1. Sensing / Five Senses Including sight, hearing, and touch.

  2. Cognition & Motor Systems Controlling actions or responses, such as movement, speed, and strength.

2.1 Sensing

The human sensory system consists of:

2.1.1 Vision

  • Visual Acuity The ability to perceive detail well, although limited. Factors that influence vision:

    • Brightness: The level of light or darkness of an object.
    • Luminance: The amount of light reflected by an object's surface.
    • Flicker: Rapid changes in light intensity.

  • Color Properties

    • Hue: Type of color (red, green, blue, etc.).
    • Intensity: Brightness or purity of color.
    • Saturation: Amount of white in the color.

Other factors: object movement and individual age.

2.1.2 Hearing

  • Frequency range: 20 Hz – 15 KHz
  • Filtering ability to separate relevant sounds from noise.

Main Sound Components

  1. Pitch: Frequency (high/low).
  2. Loudness: Amplitude (loud/soft).
  3. Timbre: Quality that distinguishes sound sources.

2.1.3 Touch

Skin has three main types of receptors:

  • Thermoreceptor: Response to temperature.
  • Nociceptor: Response to pain.
  • Mechanoreceptor: Response to mechanical pressure.

Chapter III: Human Cognition and Motor Systems

Cognitive processes relevant to computer interaction include:

  • Memory
  • Attention
  • Perception and Recognition
  • Learning
  • Problem Solving

3.1 Memory

3.1.1 Sensory Memory

  • Functions as a temporary buffer for sensory stimuli.
  • Types:
    • Iconic Memory (visual)
    • Echoic Memory (auditory)
    • Haptic Memory (touch)
  • Large capacity, very short duration, no further processing.

Human Memory Model

  1. Sensations enter Sensory Memory.
  2. Through patterns/attention → transferred to Short-Term Memory (STM).
  3. From STM → response or through rehearsal → Long-Term Memory (LTM).

3.1.2 STM & LTM

  • Short-Term Memory (STM):

    • Fast access, limited capacity (~7 ± 2 items).
    • Chunking strategy can increase capacity.
    • Prone to forgetting.

  • Long-Term Memory (LTM):

    • "Unlimited" capacity.
    • Requires time/practice to store & retrieve information.
    • Types:
      • Episodic: Sequence of events/personal.
      • Semantic: Facts & concepts.

Design Implications Related to Memory

  • Avoid forcing users to remember complex procedures.
  • Limit menu items to reduce cognitive load.
  • Prioritize recognition over recall.
  • Provide visual aids (colors, icons, markers).

3.2 Attention

  • The process of selecting information to focus on and ignoring the rest.

Design Implications

  • Design important elements to attract attention.
  • Use layout, sequence, color, animation effectively—without excess.

3.3 Perception

  • Interpretation of sensory information based on internal experience & external stimuli.

Design Implications

  • Icons should be easily distinguishable & understandable.
  • Audio notifications should be clear & different (success vs error).
  • Text must be readable: good contrast, size, spacing.

3.4 Learning

  • The process of acquiring new knowledge/skills.
  • Exploratory Learning: Learning through trial and error.

3.5 Problem Solving

  • Thinking activity to find solutions.

Design Implications

  • Provide relevant help & information.
  • Design interfaces to prevent errors.
  • If errors occur, provide descriptive & contextual messages (example: Google spell check).

Summary

Human factors in HCI represent the fundamental understanding of human capabilities and limitations that must guide the design of interactive systems. By comprehending how humans sense, process, and respond to information, designers can create more effective and usable interfaces.

Key Takeaways:

  • Sensory Limitations: Human sensory systems have specific capabilities and constraints in vision, hearing, and touch that directly impact interface design decisions.

  • Cognitive Architecture: The three-stage memory model (sensory → short-term → long-term) provides crucial insights for designing information presentation and interaction flows.

  • Attention and Perception: Understanding how humans focus attention and interpret sensory information guides effective visual hierarchy and feedback design.

  • Learning and Problem Solving: Recognizing human learning patterns helps create interfaces that support skill acquisition and effective error recovery.

  • Design Principles: Key principles include:

    • Support recognition over recall
    • Minimize cognitive load
    • Provide clear visual and auditory feedback
    • Design for error prevention and recovery
    • Use familiar patterns and metaphors

  • Individual Differences: Factors like age, experience, and physical capabilities create variation in human performance that must be accommodated in inclusive design.

Understanding human factors enables designers to create technology that works with, rather than against, natural human capabilities. This leads to interfaces that feel intuitive, reduce user frustration, and enhance overall user experience by respecting the cognitive and physical constraints of human users.