A Model for the Design of Interactive Systems based on Activity Theory

Activity theory has gained increasing popularity as a tool for the design of interactive systems. Its central idea is that user actions can only be fully understood when analyzed within the context of motive-driven activities. However, this context is currently only partially explicit in existing models; e.g. the well-known model by Engestrom promotes social aspects of context, but does not make the physical and technical environment --- relevant aspects for interactive systems design --- explicit. We present a model that incorporates the social, physical and technical context of activities. This model supports designers and developers in understanding users, their activities and the respective contexts, and allows deriving requirements for the design process directly from the model. We believe this will prove especially helpful when designing for novel devices and multi-user scenarios. We illustrate the practical use of our model with examples from two domains: composition of IT services and co-located collaborative modeling