activity-based

The venerable desktop metaphor is beginning to show signs of strain in supporting modern knowledge work. In this paper, we examine how the desktop metaphor can be re-framed, shifting the focus away from a low-level (and increasingly obsolete) focus on documents and applications to an interface based upon the creation of and interaction with manually declared, semantically meaningful activities. We begin by unpacking some of the foundational assumptions of desktop interface design, describe an activity-based model for organizing the desktop interface based on theories of cognition and observations of real-world practice, and identify a series of high-level system requirements for interfaces that use activity as their primary organizing principle. Based on these requirements, we present the novel interface design of the Giornata system, a prototype activity-based desktop interface, and share initial findings from a longitudinal deployment of the Giornata system in a real-world setting.