When system developers design a computer system (or other information artefact), they must inevitably make judgements as to how to abstract the worksystem and how to represent this abstraction in their designs. In the past such abstractions have been based either on a 'traditional' philosophy of cognition, or have been based on intuitive 'spontaneous' philosophies. A number of recent developments in cognitive psychology such as distributed cognition, activity theory and cognitive semantics have raised questions about the legitimacy of such philosophies. One area of research is to look at where the abstractions which designers employ can come from and how such abstractions are related to the concepts which the users of these systems have. One such abstraction is Data Centred Design, an approach to HCI design which recognises the importance which data and information flow and data structure has on the development of interactive systems. Another main aspect of this research is the central role that is assigned to metaphor. The notion of metaphor is not simply a linguistic expression, it is the conceptualisation of one domain in terms of another and is central to our thought processes. One of the problems with using metaphor, however, is that rarely does the whole of one domain transfer easily to another. On-going research into metaphor is vital to understanding the conceptual foundations of HCI.