It has been more than ten years since such “information appliances” as ATMs and grocery store UPC checkout counters were introduced. For the office environment, Mark Weiser began to articulate the notion of UbiComp (ubiquitous computing) and identified some of the salient features of the trends in 1991.1, 2 Embedded computation is also becoming widespread.
Microprocessors, for example, are finding themselves embedded into seemingly conventional pens that remember what they have written.3 Anti-lock brake systems in cars are controlled by fuzzy logic. And as a result of wireless computing, miniaturization, and new economies of scale, such technologies as PDAs (personal digital assistants), IM (instant messaging), and mobile access to the Internet are almost taken for granted.
But while many of the components of UbiComp that were described and anticipated by Weiser are now commonplace, major aspects of the vision are still developing. A common language for these devices has not been standardized, nor have current database solutions sufficiently captured the complexities involved in correctly expressing multifaceted data. In particular, XML is only now emerging as a viable backbone for communication within a diverse society of devices. CMSs that are now commercially available would be capable of appropriately expressing the data, but often still need to be custom-built for a given application domain. In this discussion, we focus on modeling the human aspect of interactions in the type of rich computing environment we envisage becoming commonplace.