Design Process: Interaction design basics

Notes

Study Notes

HCI Notes: Interaction Design Process

The Interaction Design Process

Foundational models and methods for designing user-centered interactive systems.

1. The Interaction Design Process (The Iterative Cycle)

The design process is generally non-linear and highly iterative, requiring constant re-evaluation and refinement. The core loop consists of four basic activities:

A. Discover/Understand

Gathering requirements and research on users, tasks, and environment (Context of Use).

B. Define/Design

Developing conceptual models, scenarios, and task flows. Moving to concrete design ideas.

C. Develop/Prototype

Building low-fidelity (sketches) or high-fidelity (interactive software) prototypes.

D. Deliver/Evaluate

Testing the prototype with users to measure usability and gathering feedback for the next iteration.

2. Conceptual and Physical Design

Design proceeds from abstract concepts (what the system does) to concrete physical implementation (how it looks and works).

A. Conceptual Design

Defines the high-level **conceptual model** of the system. This is the user's mental model—what the system is, what it does, and how it is organized.

  • **Key Tool:** **Metaphors** (e.g., the desktop, the shopping cart) which map system functions onto familiar real-world concepts.
  • **Goal:** To establish the overall structure and flow without focusing on specific screen details.

B. Physical Design

Detailed design of interfaces, interaction elements, visual hierarchy, and feedback mechanisms.

  • **Includes:** Widget choices (buttons, sliders), screen layout, color schemes, and navigational structure.

3. Core Design Activities

Requirements Elicitation

Understanding user needs and defining the system's features and goals.

  • **Techniques:** Interviews, questionnaires, focus groups, and task analysis.
  • **Output:** Functional requirements (what the system must do) and non-functional requirements (usability, performance).

Prototyping

Externalizing design ideas so they can be reviewed, tested, and communicated.

  • **Low-Fidelity:** Sketches, paper prototypes. Cheap and fast for exploring concepts.
  • **High-Fidelity:** Interactive mockups, working software. Used for final testing and developer handoff.

Evaluation

Systematically measuring the usability and learnability of the design.

  • **Methods:** Usability testing (with users), heuristic evaluation (expert review), and walkthroughs.

Conceptual Modeling (Scenario-Based)

Developing user stories and use cases to guide design decisions.

  • **Scenarios:** Detailed narratives describing a user performing a task with the system.
  • **Personas:** Fictional, yet representative, user profiles based on research data.

4. Overarching Design Paradigms

The philosophies that steer the design process.

A. User-Centered Design (UCD)

A design philosophy and process that focuses all effort on users, their needs, and the context of use at every stage.

  • **Motto:** "Know thy user." Requirements and design should always be derived from studying users.

B. Agile/Lean UX

Integrating design activities into iterative software development cycles (e.g., Scrum). Focuses on rapid feedback loops and minimal viable products (MVPs).

  • **Key Practice:** Continuous testing and adaptation based on small, incremental releases.

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