Trained in psychology and artificial intelligence. Until 1996, his research was mainly concerned with qualitative spatial representation and reasoning in humans, other animals, and computers. Since then he has concentrated on complex systems dynamics, particularly on agent-based social simulation, in the areas of land use change, energy demand, and social and informational networks. From July 1998 to July 2012 he worked at the Macaulay Land Use Research Institute, and the James Hutton Institute of which it became part.
From then to June 2020, was an independent researcher, particularly interested in ways of comparing agent-based models, and in the relationships between analysis and simulation in the study of complex systems. From July 2020, he has been employed in the School of Geography, University of Leeds, working on models of nosocomial transmission of Covid-19 in the SAFER project.