Exploring temporal ego networks using small multiples and tree-ring layouts

Many of the current dynamic network visualisations methods or techniques rely on node-link force-based models that were originally developed for visualising static network snapshots. In this study, we diverge from this traditional layout approach and develop a layout for ego networks that places the time dimension in the foreground, by turning time into an element of shape. In addition to this we develop an interactive system that enables the visualisation of multiple networks simultaneously by employing small multiples. Using the proposed layout and analytical system as a grounding visual structure, we visually characterise dynamic network events in 3 different networks; the evolution of the biotechnology field, a phone call data set and a network of passenger connections of an airline. From this analysis we propose a range of ego network visual motifs that can be used as templates to identify and characterise events that are occurring in a dynamic network.