In this paper, we seek to contribute to the Ubiquitous Computing agenda by focusing on one of its earliest, but most difficult, design ambitions - making technology "invisible in use". We draw on field studies of domestic life as this domain is becoming increasingly important for new technologies and challenges many of the assumptions we take for granted in the design of technologies for the workplace. We use some examples of domestic routines to identify a number of insights into what it means for features of activities to be "unremarkable". We conclude by using these insights to critique some of the current emphases in Ubiquitous Computing research, and suggest how we might better understand the HCI issues of what will be required to develop technologies that really are "invisible in use"

Computer supported cooperative work (CSCW) is a rapidly growing field. Real-time groupware systems are addressed that allow a group of users to edit a shared document. The architecture and concurrency control algorithm used in this system are described. The algorithm is based on the semantics of the application and can be used by the developers of other groupware systems. The authors begin by introducing the notion of a purely replicated architecture and then present GroupDesign, a shared drawing tool implemented with this architecture. They then present the main parts of the algorithm that implement the distribution. The algorithm gives the best response time for the interface and reduces the number of undo and redo operations when conflicts occur.>

This article explores real-time groupware systems from the perspective of both the users and the designer. This exploration is carried out through the description of GroupDesign, a real-time multi-user drawing tool that we have developed. From the perspective of the users, we present a number of functionalities that we feel necessary in any real-time groupware system: Graphic & Audio Echo, Localization, Identification, Age, and History. From the perspective of the designer, we demonstrate the possibility of creating a multi-user application from a single-user one, and we introduce the notion of purely replicated architecture.