title: Visual Analysis of Large Graphs Using (X,Y)-Clustering and Hybrid Visualizations.
abstract: Many different approaches have been proposed for the challenging problem of visually analyzing large networks. Clustering is one of the most promising. In this paper, we propose a new clustering technique whose goal is that of producing both intracluster graphs and intercluster graph with desired topological properties. We formalize this concept in the (X,Y) -clustering framework, where Y is the class that defines the desired topological properties of intracluster graphs and X is the class that defines the desired topological properties of the intercluster graph. By exploiting this approach, hybrid visualization tools can effectively combine different node-link and matrix-based representations, allowing users to interactively explore the graph by expansion/contraction of clusters without loosing their mental map. As a proof of concept, we describe the system Visual Hybrid (X,Y)-clustering (VHYXY) that implements our approach and we present the results of case studies to the visual analysis of social networks.
authors.forename: V
authors.initials: V
authors.lastname: Batagelj
authors.forename: F J
authors.initials: FJ
authors.lastname: Brandenburg
authors.forename: W
authors.initials: W
authors.lastname: Didimo
authors.forename: G
authors.initials: G
authors.lastname: Liotta
authors.forename: P
authors.initials: P
authors.lastname: Palladino
authors.forename: M
authors.initials: M
authors.lastname: Patrignani