Marti, P. Scrivani, P. The representation of the context in the simulation of complex systems, Cognitive Technology, vol.8, n.1, spring 2003, pp. 32-42. The representation of context in the simulation of complex systems Patrizia Marti, Petra Scrivani University of Siena Via dei Termini 6, 53100, Siena, Italy [marti ,scrivani]@media.unisi.it "neither hand or mind alone suffice; the tools and devices they employ finally shape them". Francis Bacon Keywords: Context, Activity Theory, Air Traffic Control, Memory tasks, Simulation of complex systems. ABSTRACT This paper moves from the recognition of the importance of the role of context in determining human action. By context we mean social and cultural properties of an environment as defined by Activity Theory (Kaptelinin, 1996). According to Activity Theory, human beings live in an environment that is meaningful in itself. This environment consists of entities that combine all kinds of objective features, including the culturally determined ones, which, in turn, determine the way people act on these entities. This notion of context is fundamental for understanding the role of artefacts in mediating human action. In the paper, we adopt the Activity Theory framework to reflect upon how to represent “the context” for assessing the impact of new technologies in complex systems like the Air Traffic Control (ATC). Nowadays, the validation of such technologies is mostly performed through the simulation of the operational environment, where controllers perform their activity as if they were in a real situation. In the paper, we describe an experience we made simulating the activity of an air traffic control tower in managing aerodrome traffic. The simulation was carried out using structured scenarios to represent activities really observed in the control tower and adapted to fit the context of simulation (more advanced control tools, subset of controllers working together). These scenarios offered a valid contribution toward the representation of the context in complex systems like ATC. They successfully contributed to recreate realistic situations where the system