11.2 Structural and Temporal Properties

Betweenness Centrality

The betweenness centrality of a node in a network measures the extent to which the node is part of paths that connect an arbitrary pair of nodes in the network (Brandes, 2001; C. M. Chen, 2006; Freeman, 1977).

Modularity

The modularity of a network measures the extent to which a network can be decomposed to multiple components, or modules. This metric provides a reference of the overall clarity of a given decomposition of the network (C. Chen et al., 2010).

The modularity change rate induced by a set of incoming information is considered to be a sign of a potentially important perturbation to a complex adaptive system (C. Chen, 2012).

Silhouette

The silhouette value of a cluster measures the quality of a clustering configuration. Its value ranges between -1 and 1. The highest value represents a perfect solution. However, to ensure a sound interpretation in CiteSpace, it is recommended that you should balance the modularity and silhouette scores simultaneously (C. Chen et al., 2010).

Burstness

The burstness of the frequency of an entity over time indicates a specific duration in which an abrupt change of the frequency takes place (Kleinberg, 2002). In CiteSpace, citation burst and occurrence burst are both supported.

Combined

Sigma

This indicator measures the combined strength of structural and temporal properties of a node, namely, its betweeness centrality and citation burst (C. Chen et al., 2009).