Indexicality: Understanding mobile human-computer interaction in context

A lot of research has been done within the area of mobile computing and context-awareness over the last 15 years, and the idea of systems adapting to their context has produced promising results for overcoming some of the challenges of user interaction with mobile devices within various specialized domains. However, today it is still the case that only a limited body of theoretically grounded knowledge exists that can explain the relationship between users, mobile system user interfaces, and their context. Lack of such knowledge limits our ability to elevate learning from the mobile systems we develop and study from a concrete to an abstract level. Consequently, the research field is impeded in its ability to leap forward and is limited to incremental steps from one design to the next. Addressing the problem of this void, this article contributes to the body of knowledge about mobile interaction design by promoting a theoretical approach for describing and understanding the relationship between user interface representations and user context. Specifically, we promote the concept of indexicality derived from semiotics as an analytical concept that can be used to describe and understand a design. We illustrate the value of the indexicality concept through an analysis of empirical data from evaluations of three prototype systems in use. Based on our analytical and empirical work we promote the view that users interpret information in a mobile computer user interface through creation of meaningful indexical signs based on the ensemble of context and system.