Human-Computer Interaction (HCI) Notes

Introduction to Human-Computer Interaction (HCI)

• Definition: HCI is an interdisciplinary field focused on designing and assessing computer systems that humans interact with, enhancing user-friendliness and efficiency.

• Objectives: Improve the interaction between humans and computers to increase enjoyment and efficiency in technology usage.

Principles and Heuristics of HCI

• Principles: These are broad rules based on user needs and expectations, including:

  • Ease of Use: Interfaces should be intuitive for novice users.

  • Memorability: Users should easily remember how to navigate the system over time.

  • Satisfaction: Users should enjoy a positive experience.

  • Efficiency: Tasks should be completed quickly and easily.

  • Error Prevention: Systems should help minimize user errors.

• Heuristics: Specific guidelines for assessing and improving user interfaces, largely derived from the expertise of HCI professionals. Key heuristics include Jakob Nielsen's:

  • Visibility of System Status: Users should be informed about the system’s state and receive relevant feedback.

  • Match Between System and Real World: Use familiar language rather than technical jargon.

  • User Control and Freedom: Allow users to easily undo and redo actions.

  • Error Prevention: Design should help prevent errors.

  • Recognition Rather Than Recall: Minimize the need for users to remember information; make options visible.

  • Consistency and Standards: Keep design uniform and predictable.

  • Flexibility and Efficiency: Allow users to tailor interfaces to their needs.

  • Aesthetic and Minimalist Design: Avoid unnecessary information that detracts from usability.

  • Help and Documentation: Provide easily accessible support for users.

Design Standards and Guidelines for HCI

• User-Centered Design: Design should be based on user needs assessed through research like usability testing.

• Usability: Ensure software is easy to understand and use with feedback mechanisms that aid user recovery from mistakes.

• Accessibility: Design should be inclusive, enabling usability for individuals with varying disabilities using adaptive methods (e.g., keyboard shortcuts).

• Efficiency: Help users complete tasks effortlessly using progress indicators and reducing unnecessary steps.

• Satisfaction: Ensure a pleasurable user experience through aesthetic appeal and customizability.

Interface Design Guidelines for Every Component

• General Guidelines:

  • Utilize consistent terminology.

  • Offer clear feedback.

  • Facilitate easy action reversals.

  • Prevent errors proactively.

  • Ensure accessibility in designs.

• Specific Guidelines:

  • Make labels clear and concise.

  • Design buttons and input fields large enough for usability.

  • Group related elements logically in menus and checkboxes.

  • Provide tooltips for additional information.

  • Format dialog boxes for ease of understanding.

Guidelines for Error Prevention and Handling

• Proactive Error Prevention: Offer clear instructions and feedback mechanisms to minimize user errors.

• Clear Error Messages: Use straightforward language that guides users towards fixing issues.

• Facilitate Recovery: Allow easy reversing of actions and provide support for users.

Guidelines for Visual Design

• Design Language: Maintain consistency in colors and fonts.

• White Space: Use effectively to enhance readability.

• Visual Appeal: Incorporate images and icons judiciously to avoid clutter.

Guidelines for Improving Security and Privacy

• Encryption: Implement strong encryption methods.

• Authentication/Authorization: Set up robust mechanisms to verify user identity safely.

• Data Management: Manage processed data carefully and ensure secure disposal when unnecessary.

Guidelines for Testing

• Subject applications to extensive testing on multiple devices and platforms.

• Implement automated testing to identify bugs early in development.

• Conduct usability tests with real users to uncover issues in the interface.

Usability & Accessibility Studies

• Importance: Ensure interactive systems are user-friendly and inclusive, addressing the needs of all users, including those with disabilities.

• Usability Studies: Assess ease of use, user satisfaction, and efficiency of interaction.

  • Methods include heuristic evaluations, user testing, and think-aloud protocols.

• Accessibility Studies: Identify and remove barriers for users with disabilities using methods like accessibility audits and testing with assistive technologies.

Key Differences Between Usability & Accessibility Studies

• Usability Studies: Focus on ease of use for all users, identifying issues in satisfaction and efficiency.

• Accessibility Studies: Concentrate on enabling individuals with disabilities to access systems effectively.

Summary

• HCI is a multidisciplinary field aimed at enhancing user interactions with technology through effective interface design.

• Principles and heuristics guide the development of usable interfaces.

• Usability and accessibility are critical for creating inclusive systems that cater to diverse user needs.