SNoMaN: a visual analytic tool for spatial social network mapping and analysis

Spatial social networks (SSNs) are node-link structures that evidence interpersonal or inter-organizational relationships, where nodes and edges have a defined geographic location. To model SSNs, users need both geographic and social network metrics. However, there are few GUI-based analytic tools that enable simultaneous spatial and social network exploration. In this paper, following the research framework of Exploratory Spatial Data Analysis (ESDA) and design principles of social network analysis tools, we derived three design goals of exploratory spatial social network analysis (SSNA). Guided by these design goals, we provide a visual analytic tool, SNoMaN, which links network and geographical layouts and helps users conduct SSNA by interactively computing and visualizing SSN metrics, describing spatial distributions, exploring associations, and detecting anomalies. We introduce new types of visual diagrams, including Cluster-Cluster Plots, Centralization Plots, on-the-fly mapping of geometrically bounded network modules, and Route Factor Diagrams. We illustrate these new approaches using use case studies of a 1960s network of Mafia members, a global flight network, and a food donation-sharing network in southwestern Virginia. We find that SNoMaN can be used to generate data insights that fuse a system's spatial and social dimensions that are hard to obtain otherwise.