The “Observation Urbaine” group is a resource centre for observation methods, set up to improve the relevance, comparability and reproducibility of observation. The activity is geared mainly to Ministry departments, but is also useful for technicians and project managers at observatories, engineering design offices, local authorities and other government departments. This activity is gradually focusing less on demographics and more on urban economics and the areas studied concern structural changes in urbanisation: housing, mobility, access to jobs, land use and the use of space.