Notes on User Centered Design Process (UCD) (2024)

NOTE: This page is a collection of notes onuser-centered design process (UCD). It is not intended to be comprehensive,and listing of any information here does not imply endorsem*nt byW3C.

UCD in a Sentence

User-centered design process (UCD) is also called human-centred designprocess.

Human centred design processes for interactive systems, ISO13407 (1999), states: "Human-centred design is an approach to interactivesystem development that focuses specifically on making systems usable. It isa multi-disciplinary activity."

In UCD, all "development proceeds with the user as the center of focus."(Jeffrey Rubin, Handbook of Usability Testing: How to Plan, Design, andConduct Effective Tests, John Wiley and Sons, Inc., 1984) Rubin depicts theUser-Centered Design Process as follows:

• The users are in the center of a double circle.
• The inner ring contains: Context; Objectives; Environment and Goals.
• The outer ring contains: Task Detail; Task Content; Task Organization and Task Flow.

"User-Centered Design (UCD) is a user interface design process thatfocuses on usability goals, user characteristics, environment, tasks, andworkflow in the design of an interface. UCD follows a series of well-definedmethods and techniques for analysis, design, and evaluation of mainstreamhardware, software, and web interfaces. The UCD process is an iterativeprocess, where design and evaluation steps are built in from the first stageof projects, through implementation." (Shawn Lawton Henry and Mary Martinson,Accessibility in User-Centered Design)

UCD Principles

From Jeffrey Rubin, Handbook of Usability Testing: How to Plan, Design,and Conduct Effective Tests, John Wiley and Sons, Inc., 1984:

1. Early focus on users and tasks
   • Structured and systematic information gathering (consistent across the board)
   • Designers trained by experts before conducting data collection sessions
2. Empirical Measurement and testing of product usage
   • Focus on ease of learning and ease of use
   • Testing of prototypes with actual users
3. Iterative Design
   • Product designed, modified and tested repeatedly.
   • Allow for the complete overhaul and rethinking of design by early testing of conceptual models and design ideas.

Usability

The goal of UCD is to produce products that have a high degree ofusability. ISO 9241-11 (1998) defines usability as the "extent to which aproduct can be used by specified users to achieve specified goals witheffectiveness, efficiency and satisfaction in a specified context of use."

Jeffrey Rubin describes usability objectives as:

• Usefulness - product enables user to achieve their goals - the tasks that it was designed to carry out and/or wants needs of user.
• Effectiveness (ease of use) - quantitatively measured by speed of performance or error rate and is tied to a percentage of users.
• Learnability - user's ability to operate the system to some defined level of competence after some predetermined period of training. Also, refers to ability for infrequent users to relearn the system.
• Attitude (likeability) - user's perceptions, feelings and opinions of the product, usually captured through both written and oral communication.

UCD Process Steps

While the basic principles and techniques are the same, differentvariations of user-centered design processes exist. The following example istypical of a UCD process for designing Web applications.

1. Analysis
   • Vision, goals, objectives
     Image (feeling)
     Challenges and constraints
   • User/Audience analysis
     • User Categories List
     • User Categories Matrix with knowledge, experience, and skill (KES) in www, accessibility, html, etc.; connection, environment; hardware, software; AT; frequency of use
     • Profiles (details, facts, figures)
     • Personas/Characterizations (made up "person" with name, etc.)
     • Technique: Field studies, contextual inquiry
   • Task/Purpose analysis
     • Task List
     • User-Task Matrix
   • Information architecture analysis
     • Content list
     • Content-User Matrix
     • Hierarchy, Web relationships
   • Workflow analysis
     • Workflow
     • Scenarios
2. Design
   • @@ add the usability iceberg image 10% presentation, 30% interaction, 60% conceptual model
   • Conceptual/Mental model, metaphors, design concepts
   • Navigation design
   • Storyboards, wireframes
   • Detailed design
   • Paper prototypes
   • Online mockups
   • Functional online prototypes
3. Evaluation (iterate back to Design)
   • Design walkthoughs ("cognitive walkthroughs")
   • Heuristic evaluation
   • Guidelines reviews
   • Usability testing - paper, low fidelity - high fidelity; informal - formal
4. Implementation
5. Deployment

More Information

The WAI Resource Involving Users in WebAccessibility Evaluation provides guidance on including peoplewith disabilities ("users") in accessibility evaluation throughout Webdevelopment, including in user-centered design.

There are myriad resources resources on usability, UCD, and related topicsavailable on the Web, in books, etc. UsableWeb is a thorough list of resources on Web usability. It is no longerupdated, yet does include other usability resource lists.

Justin Thorp compiled a short list of UCD and UTResources, which provides links to on-line resources.