Keywords: distributed cognition, accident causation, assumption making, systems design
The role of distributed cognition in the causation of accidents
The notion that, in many situations, cognition is distributed provides a significantly different perspective for understanding past failures in sociotechnical systems, and for reasoning about future risks. In this study, a set of reports of accidents on offshore installations was analysed in an attempt to discover how the distribution of cognition contributed to accident causation. The assumptions about the world implied in the various patterns of distribution were identified, and these were grouped in an attempt to say how distribution made systems vulnerable. A model was then developed to express some general observations: for example the fact that distribution was generally entrained in people's activity, not deliberately planned. A significant conclusion was that systems designers should use results of this kind in their risk analyses. In particular, they should test how their systems are likely to respond to the kinds of flawed assumptions that were revealed in the study.