User-Centered Design in a Nutshell

Great designs don't just happen. They're the result of applying user-centered design principles and methods throughout the development process.

User-centered design provides a structured method for achieving usability in user interface design. The methodology:

  • emphasizes an early focus on users and their tasks
  • promotes a top-down approach, dealing with high-level design issues first
  • is iterative
  • is scalable, based on the time and resources available to the project
  • can be integrated with the software development lifecycle.

The table below summarizes the major tasks in user-centered design.

Phase 1: Requirements Analysis
Task
Purpose
Techniques
Deliverables
User Profiles
Establish user characteristics around which the UI design should be tailored.
Questionnaire distributed to users.

Interviews with people knowledgeable about users.
Data summary and analysis in requirements spec.
Task Analysis
Obtain a user-centered model of work as it is currently performed.
Observe users doing real work in their actual work environment.

Interview users.

Interview people knowledgable about user work tasks and environment.
Task scenarios and task analysis in requirements spec.
Goal Setting
Establish specific qualitative and quantitative usability goals that will drive UI design.
Extract goals from user profile and task analysis.

Extract goals from general business goals.
Documented qualitative and quantitative usability goals in requirements spec.

Phase 2: Design
Task
Purpose
Techniques
Deliverables
Conceptual Design
Establish a coherent and rule-based high-level UI design framework.
Generate overall presentation rules.

Develop diagrams and prototypes.
Diagrams and mockups representing the conceptual design.
Conceptual Design Evaluation
Evaluate, refine, and validate the conceptual design.
Usability testing.

Usability inspection.
Results fed back into conceptual design.
User Interface Design
Design the complete, detailed user interface.
Generate screen design standards.

Apply screen design standards to design the UI of all product functionality.
Prototype of user interface

Detailed user interface design spec.
User Interface Design Evaluation
Evaluate, refine, and validate key subsets of the detailed user interface design.
Usability testing.

Usability inspection.
Results fed back into user interface prototype and specs.

Phase 3: Implementation
Task
Purpose
Techniques
Deliverables
User Feedback
Obtain usability data after the product has been installed and used.

Inform the UI design for later releases of the product and related products.
Usability testing.

Questionnaires.

Interviews.

Focus groups.

Usage studies.
Usability feedback.

Charts adapted from "The Usability Engineering Life Cycle," by Deborah Mayhew