Peut-on se fier à l'information spatiale extraite des données TIC ?

Abstract

International audienceWhile an increasing number of human activities are studied using data produced by individuals' ICT devices, there have been relatively few contributions investigating the robustness of results against fluctuations of data characteristics. In particular, when ICT data contain spatial information, they represent an invaluable new source for analyzing urban phenomena. Here, we present a stability analysis of higher-level information extracted from mobile phone metadata passively produced during an entire year by 9 million individuals in Senegal. We focus on two specific information-retrieval tasks: (a) the identification of land use in the region of Dakar by analyzing the temporal rhythms of the communication activity; (b) the identification of home and work locations of anonymized individuals, allowing for the construction of the Origin-Destination (OD) matrices for commuting flows. Our analysis reveals that the spatial distributions of land use computed for different samples are remarkably robust, with on average 80% of shared surface area between the different spatial partitions. The OD matrix is less stable with a share of about 70% of commuters in common when considering all types of flows. Better results can be obtained at larger levels of aggregation. These different results confirm that ICT data are mostly a very useful source for the spatial analysis of urban systems, but that their reliability should be tested more thoroughly