This dissertation addresses the role of tools in social interactions, or more precisely the significance of tools in cognition and cooperation, from a situated cognition perspective. While mainstream cognitive science focuses on the internal symbolic representations and computational thought processes inside the heads of individuals, situated cognition approaches instead emphasise the central role of the interaction between agents and their material and social environment. This thesis presents a framework regarding tools and (some) of their roles in social interactions, drawing upon work in cognitive science, cultural-historical theories, animal tool use, and different perspectives on the subject-object relationship. The framework integrates interactions between agents and their environment, or agent-agent-object interaction, conceptualisations regarding the function of tools, and different ways in which agents adapt their environments to scaffold individual and social processes. It also invokes stigmergy (tool mediated indirect interactions) as a mechanism that relates individual actions and social activity. The framework is illustrated by two empirical studies that consider tool use from a social interaction perspective, carried out in settings where tools assume a central role in the ongoing collaborative work processes; a children’s admission unit in a hospital and the control room of a grain silo. The empirical studies illustrate theoretical issues discussed in the background chapters, but also reveal some unforeseen aspects of tool use. Lastly, the theoretical implications for the study of individual and social tool use in cognitive science are summarised and the practical relevance for applications human-computer interaction and artificial intelligence is outlined.

Geoscience operates at the boundary between two worlds; the visible and the invisible. Increasingly, new geological technologies such as hydraulic fracturing, carbon capture and storage (CCS) and radioactive waste disposal are drawing the public’s attention to the ‘invisible’ world of the geological subsurface. This presents unique communication challenges because these technologies exist in a realm that can never be physically seen. This thesis addresses this issue by examining the psychological perceptions of residents in three villages in the south west of England. A representative sample from each village was qualitatively interviewed and mental models were constructed from the resultant data using the ‘mental models’ technique (Morgan et al, 2002). The mental models were then quantitatively tested using a questionnaire to assess the perceptions that a broader sample of the residents of these locations hold towards the geological subsurface. The results from the mental models assessment identified the principal perceptions held by the majority of the public surveyed. In particular, the study revealed the connection between the visible surface and the invisible subsurface and how different participants engaged with that boundary; choosing either a geoscience-centric or an anthropocentric approach to penetrating the surface. These approaches utilised by non-experts differed from those employed by the experts, who used a regionally specific geoscience-centric approach to visualising the subsurface. The work provides an important empirical baseline from which to develop a science-led strategy to engage the general public with new technologies and to increase our understanding of the more broadly held conceptions of the invisible subsurface.