Human-Computer Interaction Overview

Study Notes

Human-Computer Interaction (HCI)

User Interface (UI): The point of interaction and communication between a human and a computer device.
HCI: Aims to improve the design of interfaces to increase productivity, enhance user experience, and minimize risks in critical systems.
Applications: A broad category encompassing different types of software including games, media and information, electronic commerce, design and editing tools, and social networking services.
User Types: Represent distinct user segments based on their age (e.g., kids, elders, baby boomers), ability (e.g., visually challenged), or other factors.
Understandable Principle: Designs are user-friendly, preventing confusion and errors.
Display Layout Guidelines: To ensure clear and organized displays, consider factors such as:
- Avoiding clutter
- Consistent placement of important elements
- Optimizing display density
- Using alignment
- Setting appropriate page lengths
- Selecting appropriate line lengths
- Utilizing frames for readily accessible functions
Avoid Semantic Oppositions: A guideline to avoid conflicting or confusing user input options.
Six HCI Principles:
- Know the user: Understand your target audience's needs and abilities.
- Understand the task: Analyze the tasks users perform, their goals, and the context of their interaction.
- Reduce memory load: Design interfaces that minimize the need for users to remember complex instructions or information.
- Strive for consistency: Ensure consistent layout, terminology, and functionality across the interface.
- Remind users and refresh their memory: Provide cues, prompts, and feedback to guide users.
- Naturalness: Align interface design with users' natural expectations and mental models.
Fierce Task Focus: A mobile device guideline emphasizing prioritizing the most crucial elements for user interaction to avoid confusion.
Operable Principle: Users with disabilities can interact with the interface using only a keyboard, ensuring accessibility.

Human Perception and Cognition

Field of View (FOV): The area visible to the user when looking in a specific direction, both horizontally and vertically.
Color Components: Hue, saturation, and brightness are the fundamental building blocks of color perception.
HCI Design Elements: The core elements of good HCI design are:
- Understanding the computer: Knowledge of the computer's capabilities and limitations.
- Human Behavior: Understanding how users interact with technology and their cognitive processes.
Memory: A key cognitive function responsible for storing and retrieving information.
Motor Control: The ability to control body movements, particularly the arms, hands, and fingers, essential for interacting with devices.
Haptic Feedback: Using touch-based feedback through force, vibrations, or motions to enhance user interaction.
Tactile Resolution: The sensitivity of the skin to touch, varying across different areas, especially high in the fingertips, which are crucial for interaction.
Problem-Solving Components: Sensation, perception, memory, and decision-making are the core elements of human problem-solving.
Cones and Rods: Two types of light-sensitive cells in the eye. Cones are responsible for color and detail recognition, while rods detect motion and peripheral vision.
Intensity: The strength or power of a sound wave, often referred to as volume.

User Interface (UI) Layers and Interactive Applications

UI Layer Components: Two key components of the UI layer:
- API: The Application Programming Interface, enabling communication and interaction between applications and the UI.
- Window Manager: Manages windows, providing the user interface elements (buttons, menus, etc.) for interaction.
Input and Output Handling: Input and output events are handled by interrupt mechanisms in the system software.
GUI-based Interactive Applications: Typical structure includes:
- Top Window: A rectangular area of the screen dedicated to a specific application, serving as a platform for interaction.
- Window: A rectangular portion of the screen representing a specific application for interaction.
Interactive Applications: Implemented and executed using the UI software layers (API and window manager).

HCI Concepts:

Ergonomics in HCI: This involves designing interfaces to minimize physical strain, optimize comfort, and prevent injuries for users.
Usability vs. User Experience:
- Usability: Focuses on the efficiency and effectiveness of the user interface in accomplishing tasks.
- User Experience: Encompasses the overall emotional response and satisfaction users have with the interface.
Accessibility in HCI: Designing inclusively to cater to users with disabilities. This involves ensuring the interface is navigable and usable by everyone.
Interactive System Components: The core components of an interactive system in HCI are:
- User Interface: The visual and interactive elements users interact with.
- Input: The way users provide instructions or data to the system.
- Output: How the system presents information or responses to the user.