User-centered design

User-centered design (UCD) or user-driven development (UDD) is a framework of process (not restricted to interfaces or technologies) in which usability goals, user characteristics, environment, tasks and workflow of a product, service or process are given extensive attention at each stage of the design process. These tests are conducted with/without actual users during each stage of the process from requirements, pre-production models and post production, completing a circle of proof back to and ensuring that "development proceeds with the user as the center of focus." Such testing is necessary as it is often very difficult for the designers of a product to understand intuitively the first-time users of their design experiences, and what each user's learning curve may look like. User-centered design is based on the understanding of a user, their demands, priorities and experiences and when used, is known to lead to an increased product usefulness and usability as it delivers satisfaction to the user. The chief difference from other product design philosophies is that user-centered design tries to optimize the product around how users can, want, or need to use the product so that users are not forced to change their behavior and expectations to accommodate the product. The users thus stand in the center of two concentric circles. The inner circle includes the context of the product, objectives of developing it and the environment it would run in. The outer circle involves more granular details of task detail, task organization, and task flow. The term "User-Centered Design" was coined by Rob Kling in 1977 and later adopted in Donald A. Norman's research laboratory at the University of California, San Diego. The concept became widely popular as a result of the publication of the book User-Centered System Design: New Perspectives on Human-Computer Interaction in 1986. The concept gained further attention and acceptance in Norman's seminal book The Design of Everyday Things (originally called The Psychology of Everyday Things).