The creation of GUIs poses a challenge, because an appropriate model of reality
or an acceptable conceptual model of the representation must be invented.
Designing GUIs for use on intranets, extranets, and, more pressingly, on the Web
requires even more careful planning (see Chapter 12 on Web site design). By and
large, the users of Web sites are unknown to the developer, so a design must be
clear-cut. The choice of icons, language, and hyperlinks becomes an entire set of
decisions and assumptions about what kinds of users the Web site is hoping to
attract. The designer must also adhere to conventions that users now expect to
encounter on Web sites.