We conducted an ethnographic study  in which we observed and interviewed several professional web designers. This study showed that the process of designing a web site involves an iterative progression from less detailed to more detailed representations of the site. For example, designers often create site maps early in the process, which are high-level representations of a site in which each page or set of pages is depicted as a label. They then proceed to create storyboards of interaction sequences, which employ minimal page-level detail and focus instead on the navigational elements required to get from one page to another. Later still, designers create schematics and mock-ups, which are different representations of individual pages.
These were the primary observations that led to the design and implementation of DENIM , a system to assist web designers in the early stages of information, navigation, and interaction design. DENIM is an informal pen-based system that allows designers to quickly sketch web pages, create links among them, and interact with them in a run mode. The different ways of viewing a web site, from site map to storyboard to individual pages, are integrated through the use of zooming.
More information is available through the Group for User Interface Research web site at http://guir.berkeley.edu.
Figure 1: The DENIM system