HCI Prelim 1

• World War II: Interest in building more effective weapons
• World War II: Led to the study of humans and machines
• Ergonomics Research Society was stablished in 1949.
• Ergonomics Research Society was established in 1949.
• Ergonomics Research Society focused on physical characteristics of machines and systems and how these affect human performance.
• Ergonomics and Human Factor: Both disciplines are concerned with user performance in the context of a system
• HCI became a popular term in the 1980s.
• HCI became a popular term in the 1980s.
• HCI is specialized field of study concerned with the interaction between people and computers.
• HCI is concerned with the physical, psychological and theoretical aspects of the process.
• Four major components of HCI

  • The computer

  • The human being

  • The task

  • Usability
• Useful: Object accomplishes what is required
• Usable: Object accomplishes what is required easily and naturally, without danger or error
• Used: Object is attractive, engaging, fun—people WANT to use it
• Affordances are the design aspects that indicate how an object should be used, almost like visual clues.
• Constraints in design serve as guides or guardrails, preventing users from making errors and directing them towards the intended use of a product.
• Constraints can be physical (like the shape of a USB plug that only allows it to be inserted in one orientation).
• Constraints can be cultural (such as red for stopping and green for going).
• Constraints can be logical (like graying out unavailable options in a software menu).
• Constraints help to simplify decision-making and usage, ensuring a smoother user experience.
• Conceptual models are the mental representations people form of how things work.
• Conceptual models help users predict the outcomes of their interactions with a system.
• Conceptual models are crucial in design because they help bridge the gap between a user’s expectations and the product’s functioning.
• Mappings refer to the relationship between controls and their effects in a system.
• The principle of visibility emphasizes the importance of making necessary elements visible and accessible to users while minimizing the visibility of non-essential elements.
• Visibility helps in reducing the user’s cognitive load by making options and paths to action clear.
• Feedback in design is about communicating back to the user that an action has been registered and what the result of that action is.
• HCI is concerned with these three: Sight, Hearing, Touch
• Human beings can hear sounds from 20 Hz to 15 kHz.
• Human beings can distinguish frequency changes of less than 1.5 Hz at low frequencies.
• Haptic perception - important means of feedback
• If we can see an object but not feel it, speed and accuracy of a response is reduced.
• Touch: Complaint of VR users
• Human memory three types:

  • sensory buffers
  • short-term memory
  • long-term memory
• Iconic - visual

  • persistence of the image after the stimulus has been removed
• Echoic - aural

  • allows a brief “play-back”
• Echoic memory is the sensory memory for sounds, briefly holding audio information for recall within a few seconds after input.
• Short-term memory: Scratch-pad for temporary recall
• Short-term memory: Used for information needed fleetingly
• Short-term memory: Rapid access, limited capacity