This book presents a contextual approach to designing contemporary interactive mobile computer systems as integral parts of ubiquitous computing environments. Interactive mobile systems, services, and devices have become functional design objects that we care deeply about. Although their look, feel, and features impact our everyday lives as we orchestrate them in concert with a plethora of other computing technologies, these artifacts are not well understood or created through traditional methods of user-centered design and usability engineering. Contrary to more traditional IT artifacts,...