Raphaëlle Nollez-Goldbach

Analysing the first case of the International Criminal Court from a network-science perspective

This paper analyses the multi-level network composed of the legal decisions taken by the International Criminal Court since its creation in 2002. As many real-world networks, legal networks lend themselves to the use of graphs in which nodes represent the decisions taken by the Court and links stand for citations between decisions. Although useful, this framework does not account for the inherent complexity and hierarchy commonly observed in real data. In the context of legal networks in particular, interactions between decisions take place at various levels, inducing a two-level structure. We propose here to rely on a hybrid version of bipartite graphs, which allows to represent different types of links in multi-level networks. We assess the relevance of this approach by analysing the hybrid structure of the first case of the Court and by confronting it with standard approaches focusing on direct citation processes. We validate the outcomes by providing juridical interpretations of the results, which shed some light on the procedural aspects of the International Criminal Court and put an emphasis on the key themes addressed by this jurisdiction. Thus, for the first time, this work converges two very different approaches to account for the multi-level complexity in legal networks. Complex networks, bipartite graph, legal network, International Criminal Court.

Temporal properties of legal decision networks: a case study from the International Criminal Court

Many studies have proposed to apply artificial intelligence techniques to legal networks, whether it be for highlighting legal reasoning, resolving conflict or extracting information from legal databases. In this context, a new line of research has recently emerged which consists in considering legal decisions as elements of complex networks and conduct a structural analysis of the relations between the decisions. It has proved to be efficient for detecting important decisions in legal rulings. In this paper, we follow this approach and propose to extend structural analyses with temporal properties. We define in particular the notion of relative in-degree, temporal distance and average longevity and use those metrics to rank the legal decisions of the two first trials of the International Criminal Court. The results presented in this paper highlight non trivial temporal properties of those legal networks, such as the presence of decisions with an unexpected high longevity, and show the relevance of the proposed relative in-degree property to detect landmark decisions. We validate the outcomes by confronting the results to the one obtained with the standard in-degree property and provide juridical explanations of the decisions identified as important by our approach.