Some definitions of distributed cognition
The Distributed Cognition approach emphasizes the distributed nature, in time and space, of cognitive phenomena across individuals, artifacts and internal and external representations. Starting from this assumption, this approach disputes the mainstream divisions between the inside/outside boundary of the individual and the culture/cognition. (Gabrielli, 2000).
The distributed cognition approach aims to show how intelligent processes in human activity transcend the boundaries of the individual actor. Hence, instead of focusing on human activity in terms of processes acting upon representations inside an individual actor's heads the method seeks to apply the same cognitive concepts, but this time, to the interactions among a number of human actors and technological devices for a given activity.
Within the distributed cognition framework, therefore, one can adopt different units of analysis, to describe a range of cognitive systems, whereby some subsume others. One can focus on the processes of an individual, on an individual in coordination with a set of tools or on a group of individuals in interaction with each other and a set of tools. At each level of description of a cognitive system, a set of cognitive properties can be identified; these properties can be explained by reference to processes that transform states inside the system. (Rogers, 1997)