Gradually, richer patterns of interface usage are appearing, resembling what
Christopher Alexander has described for architecture (1977). Familiar patterns
of building fireplaces, stairways, or roofs become modular components that
acquire names and are combined to form still larger patterns. Patterns are akin
to guidelines, with the distinguishing feature that patterns promise an orderly
structure of problem, context, solution, examples, and cross-referencing. Pat-
terns for human-computer interaction-such as "multiple ways to navigate;"
"process funnel," and "internationalized and localized content"-have been
identified for desktop applications, web design (Van Duyne, Landay, and Hong,
2002), and mobile devices.