User Centered Design

User-centered design (UCD) is an approach to design that grounds the process in information about the people who will use the product. UCD processes focus on users through the planning, design and development of a product.

ISO 13407: Human-centred design process

There is an international standard that is the basis for many UCD methodologies. This standard (ISO 13407: Human-centred design process) http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=21197 defines a general process for including human-centered activities throughout a development life-cycle, but does not specify exact methods.

The User Centered Design Process

In user centred design, once the need to use a human centered design process has been identified, four activities form the main cycle of work:

1. Specify the context of use - Identify the people who will use the product, what they will use it for, and under what conditions they will use it.
2. Specify requirements - Identify any business requirements or user goals that must be met for the product to be successful.
3. Create design solutions - This part of the process may be done in stages, building from a rough concept to a complete design.
4. Evaluate designs - The most important part of this process is that evaluation - ideally through usability testing with actual users - is as integral as quality testing is to good software development.

The Gulf of Execution

 In a typical web design project a gulf of execution exists between three different perceptions of the design:

1. The Business Model - held by senior managers who want sell particular products or services, who see thier company structured in a particular way and know  particular information about the company and its history.

2. Designers Model  - the developers may want to use a particular architecture or the latest cool technology. May have constraints about how the database can accept data

3. Users Mental Model  - I want to buy this product, I want to register for update, I need to find this information

User centred design tries to bridge the Gulf of Execution.

A Typical User Centered Design Project

User Centred Design has 4 phases:

Analysis Phase

Meet with key stakeholders to set vision
Include usability tasks in the project plan
Assemble a multidisciplinary team to ensure complete expertise
Develop usability goals and objectives
Conduct field studies
Look at competitive products
Create user profiles
Develop a task analysis
Document user scenarios
Document user performance requirements

Design Phase

Begin to brainstorm design concepts and metaphors
Develop screen flow and navigation model
Do walkthroughs of design concepts
Begin design with paper and pencil
Create low-fidelity prototypes
Conduct usability testing on low-fidelity prototypes
Create high-fidelity detailed design
Do usability testing again
Document standards and guidelines
Create a design specification

Implementation Phase

Do ongoing heuristic evaluations
Work closely with delivery team as design is implemented
Conduct usability testing as soon as possible

Deployment Phase

Use surveys to get user feedback
Conduct field studies to get info about actual use
Check objectives using usability testing

Usability testing is an important part of the Design, Implementation and Deployment phases

More info:
Wikipedia Article

ISO 13407

What is User Centered Design according to the Usability Professionals Association

User-centered Website Development: A Human-Computer Interaction Approach by Daniel D. McCracken, Rosalee J. Wolfe, Jared M. Spool