Seamful design: showing the seams in wearable computing

In this paper, we question the assumption that seamless integration of computer system components is necessarily a design requirement for wearable computing and for ubiquitous computing. We explore Mark Weiser's notions of seamlessness and 'seamfulness', and use them in discussing the design and use of wearable and ubicomp systems. The physical nature of the systems we design reveals itself in, for example, uncertainty in sensing, limited coverage of communications infrastructure and the transformations needed to share data between heterogeneous tools and media. When such seams show through, as they inevitably do, users perceive and appropriate them for their own uses. We suggest that new opportunities for system design arise if we take fuller account of this process, and consider making it a deliberate policy to reveal and use seams. We offer examples of seams and some suggestions for seamful design, drawing from the Equator interdisciplinary research collaboration's work on ubiquitous computing and mixed reality systems. More particularly, we focus on our work in Equator's City project, on a system that lets a visitor using a PDA in a museum exhibition or cultural institution co-visit with people using virtual reality and Web versions of the same institution. Our work is strongly influenced by the vision of ubiquitous computing presented by Mark Weiser.