If you build it, they will come. Well, that depends on how you've built it. If you've built it badly, they almost certainly won't come back.

Many technological innovations rely upon User Interface Design to elevate their technical complexity to a usable product. Technology alone may not win user acceptance and subsequent marketability. The User Experience, or how the user experiences the end product, is the key to acceptance. And that is where User Interface Design enters the design process.

When the interface is well designed, it is comprehensible, predictable, and controllable - users feel competent, satisfied, and responsible for their actions. In web design, the person who is responsible to design an interface that is intuitive, easy to use, and allows the users to maximize their efficiency and effectiveness is called a user interface (UI) designer.

A UI designer will work closely with an Information Architect and technologists to ensure that the interface supports the architecture. In a usage-centered design approach the UI designer will focus more on what the user likes, and what they will expect from the site. It is the UI designer that will dig in up to the elbows to understand the users and the tasks they perform in order to design interfaces that will produce the best user interaction and experience.