In the context of team Cornet’s seminars, Sébastien De Valeriola (Free University of Brussels) will present his research work on “Fading Footprints in the Sand”: Analysis of Historical Networks and Robustness of Centrality Metrics, on February 10, 2023, at 11:35 in the room S6.
Abstract: In this presentation, we consider centrality measures in their use in the analysis of historical networks. Since the sources used by historians to construct such networks are inherently incomplete and imperfect, it is necessary to take into account the robustness of these metrics as much as possible, i.e., their stability in the face of the vagaries that time has subjected historical documents to. To study this, we apply a battery of tests to three networks constructed from medieval history data. The first is a network of political history, representing the connections among the key figures in the conflict for the episcopal seat of Cambrai in the 11th century. The second is a network of socio-economic history, describing credit relationships among merchants in Ypres in the 13th century. The third is a hagiographical network depicting the connections between the lives of saints often compiled together in manuscripts. These tests are designed to simulate the processes of information disappearance and degradation contained in sources by closely mimicking situations historians encounter when working with graphs. In each of them, we create a large set of new graphs by transforming the original graphs and observe the effect of these transformations on centrality metrics. We use a random process for this, but one that respects the characteristics of the considered networks, which are built from historical sources. Our results allow us to assess the general relevance of using centrality in the analysis of historical networks, compare the four studied metrics in terms of robustness, and identify a set of methodological points to which historians applying these techniques should pay particular attention.