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,‎ they constitute holistic user experiences of value and pleasure that require careful attention to the variety‎,‎ complexity‎,‎ and dynamics of their usage‎.‎ Hence‎,‎ the design of mobile interactions proposed in this book transcends existing approaches by using the ensemble of form and context as its central unit of analysis‎.‎ As such‎,‎ it promotes a designerly way of achieving convergence between form and context through a contextually grounded‎,‎ who‎.‎‎.‎‎.‎