User Interface Design Notes

  • User Interface Design Principles

    • Key factors for effective interface design include:
    • Easy to learn
    • Easy to use
    • Easy to understand

  • Design Issues

    • Common errors in interface design:
    • Lack of consistency
    • Too much memorization required
    • Absence of guidance/help
    • No context sensitivity
    • Poor response times
    • Unfriendly design

  • Golden Rules of Interface Design

    • Place the User in Control
    • Define interaction modes to avoid unnecessary actions
    • Flexible and interruptible interactions
    • Streamline for advancing skill levels
    • Hide technical details from casual users
    • Design for direct interaction with screen objects
    • Reduce Memory Load
    • Minimize short-term memory demands
    • Use meaningful defaults and intuitive shortcuts
    • Base visual layout on real-world metaphors
    • Gradually disclose information
    • Make the Interface Consistent
    • Provide meaningful context for tasks
    • Maintain consistency across applications
    • Avoid changes that disrupt user expectations without compelling reasons

  • User Interface Design Models

    • System Perception: User’s mental image of the interface
    • User Model: Profile of end users
    • System Image: Complete interface representation
    • Design Model: Data, architecture, interface, and procedures of the software

  • Design Process Steps

    1. Analyze user, tasks, and environment
    2. Interface design
    3. Validation of the interface implementation

  • Task Analysis and Modeling

    • Define and classify tasks required by the interface
    • Identify objects and actions for each task
    • Iteratively refine tasks until fully defined

  • Interface Design Activities

    1. Establish goals and intentions for tasks
    2. Map goals to specific actions
    3. Specify action sequences (user scenarios)
    4. Indicate system state during task performance
    5. Define control mechanisms for altering system state
    6. Show effects of control mechanisms on system state
    7. Indicate user interpretation of system state from interface info

  • Design Evaluation Cycle

    • Initial design
    • Prototype building and user evaluation
    • Modifications based on evaluation