• The design is based upon an explicit understanding of users, tasks, and environments.

You must understand your users and what they want to do with the system. This understanding is arrived at by directly observing their behavior in context.

• Users are involved “throughout” design and development.

User’s involvement should be active. You involve users by carrying out field studies to understand users’ needs, by showing users early design concepts and by usability testing prototypes.

• The Design is Driven and refined by user-centered evaluation.

Initially, in the development process, intended users should carry out real tasks and their performance and reactions should be observed, recorded and analyzed.

“Shut up, sit and observe”

–David Travis

• The process is Iterative.

When problems are found during user testing (as they will be) they must be fixed. This means design must be iterative; there must be a cycle of design, test, and measure and redesign repeated until the usability objectives are met.

– Yuvraj Naruka