Notes on Human Computer Interaction - CS310

Human Computer Interaction Overview

  • Human Component

    • Sensory Systems:
    • Vision
    • Hearing
    • Touch
    • Movement
    • Acting Systems:
    • Hands
    • Voice
    • Head, Body
    • Cognitive Processes:
    • Perception
    • Memory

  • Computer Component

    • Input Peripherals:
    • Keyboard, mouse
    • Trackpad, trackball
    • Touch surfaces/screens
    • Microphones, sensors, card readers
    • Output Peripherals:
    • Screens
    • Audio (voice/sounds)
    • Haptics
    • VR/AR headsets

Memory Structure

  • Long-Term Memory (LTM)
    • Capacity: extLTM=ext∞ext{LTM} = ext{∞}
    • Type: Semantic memory
  • Working Memory (WM):
    • Capacity: extWM=3ext{WM} = 3 to 77 chunks
    • Duration: 77 seconds to 226226 seconds for 1 chunk.
  • Short-Term Memory (STM):
    • Capacity: extSTM=7ext±2ext{STM} = 7 ext{±} 2 chunks (Miller’s Law)
    • Duration: 15−3015-30 seconds
    • Relies on repetition, notes, bookmarks.
    • Chunking: Organizing information to enhance memory.

Perception vs. Reality

  • Visual Processing:
    • Transformation and interpretation from retina input
    • Expectations alter image perception
  • Optical Illusions:
    • Examples include different perceptions of line lengths and colors (e.g., "What color is this dress?")
  • Interpretation Stages:
    • Bottom-Up: Physical reception of stimuli
    • Top-Down: Processing based on prior experiences

The Role of Vision in HCI

  • Visual Hierarchy:
    • Importance of layout affects understanding; use size, prominence, and content relationships.
  • Error Indicators:
    • Use visual cues to indicate errors clearly (e.g., placing messages in users' line of sight)
  • Improving Usability:
    • Design should support perceptual grouping, chunking, and enable easy visual scanning.

Interaction Design Principles

  • Structure interfaces to support cognitive processes:
    • Minimal Loading: Reduce load on STM to enhance usability (example: Google’s simple interface)
    • Color & Shape: Use distinct features to aid memory.
    • Effective Chunking:
    • Group information meaningfully to improve retention (e.g., group serial numbers or topics)
  • Long-Term Memory:
    • Stores extensive knowledge; access is slower compared to STM.
    • Types: Declarative (factual) vs. Procedural (skills).

Practical Applications

  • Activity Example:
    • Remember the numbers 62,10,7,2362, 10, 7, 23 displayed at the start of the class as a test of working memory capacity.