A lot of research has been done in the area of context-aware computing. Even though, the term context seems often not to be well defined. We attribute this problem partly to the fact that research often focuses on syntactical and technical issues of contextuality and does not take a knowledge level perspective on context. When including the knowledge level, some sort of analysis is required on what aspects need to be modelled. In this paper, we propose the use of an Activity Theory (AT) based approach on modelling components, and outline how it can be combined with the AmbieSense context modelling framework we have proposed earlier.