ITEC 3230 Prototyping and User Interface Design Notes

Announcements

• Mid-term exam: 1 hour, covers all previous lectures plus today’s lecture.

Exam Question Types

• True/False Examples:

  • Horizontal prototypes include in-depth functionality for a few selected features.

• Multiple Choice Example: What interaction style supports the recognition rather than recall principle?

• Brief Explanation: Compare and contrast between simple observation and think-aloud protocol.

• Interface Critiques: Identify design principle violations in a sample interface.

Conceptualizing Interaction

• Orientation: Ask specific questions about the conceptual model's understanding.

• Open-mindedness: Avoid narrow focus early in the design process.

• Common Ground: Establish a set of commonly agreed terms to avoid assumptions.

User Reactions to Technology

• 3D TV Example:

  • Will people wear special glasses in their living rooms? Mixed responses expected about clarity and user comfort.

Conceptual Model

• High-level description of a system's organization and operation involving:

  • Metaphors/Analogies: Use familiar references, e.g., icons, tables.

  • Concepts: Define core ideas like saving and organizing.

  • Relationships: Understanding the problem space and design space.

Interface Styles and Interaction Types

• Types of Interfaces:

  • Command Language: Intended for expert users.

  • Direct Manipulation: Emphasizes physical actions and immediate feedback (Shneiderman 1983).

  • Menus and Forms: High learnability, offering recognition over recall.

  • Speech Dialog: Suitable for novice users but may lack clear affordances.

Prototyping Process

1. Identification: Identify users and their tasks.

2. Requirements: Decide which tasks and users the design supports.

3. Design: Create design representations and dialog sequences.

4. Evaluations: Test the prototype through user interaction.

Participatory Design

• Users as first-class members in the design process.

• Benefits include leveraging users’ extensive contextual knowledge.

• Challenges include cost and user reluctance to engage.

Prototyping Methods

• Low-Fidelity Prototyping: Quick paper prototypes to brainstorm designs and elicit user feedback.

• Medium-Fidelity Prototypes: More detailed simulations that can test subtle design issues but may limit user engagement.

• High-Fidelity Prototypes: Fully functional systems used for usability testing.

• Wizard of Oz Method: Simulates a system that currently does not exist, allowing feedback on conceptual design.

Evaluation Techniques

• Heuristic Evaluation: Checklist of design principles to assess usability.

• Cognitive Walkthrough: Focuses on how well new users can navigate the interface through task sequences.

• Predictive Models: Estimate the efficiency of designs using metrics like GOMS and Fitts' law.

Design Principles

• Visibility: Ensure users are aware of system actions.

• Affordances: Design elements should suggest their usage.

• Constraints: Help prevent user errors involving incorrect selections.

• Consistency: Maintain similar operations across platforms and applications.

• Simplicity: Streamline designs to convey messages without unnecessary complexity.

• Learnability: Utilize familiar metaphors and concepts to aid user understanding.

Visual Design Elements

• Layout: Group related items, use whitespace effectively, establish hierarchy.

• Color: Maintain few colors for clarity, avoid saturation to prevent fatigue.

• Typography: Understand differences between serif and sans serif fonts, use consistent fonts across a design.

Summary of Evaluation Approaches

• Participatory Design: Involves users actively; may require more resources.

• Analytical Evaluations: Utilize heuristics and cognitive tests without real user interaction to assess systems.