Social Network Analysis, Graph Theoretical Approaches to

Abstract

Social network analysis (SNA) focuses on the structure of ties within a set of social entities or actors, e.g., persons, groups, organizations, and nations, or the products of human activity or cognition such as semantic concepts, web sites, and so on. In a graph theoretical approach, a social network is conceptualized as a graph, that is, a set of vertices (or nodes, units, points) representing social actors and a set of lines representing one or more social relations among them. A network, however, is more than a graph because it contains additional information on the vertices and lines. Characteristics of the social actors, for instance, a person’s sex, age, and income, are represented by discrete or continuous attributes of the vertices in the network, and the intensity, frequency, valence, and type of social relation are represented by line weight or value, line sign, or line type. Formally (see pp. 94–95, 127–128 in Doreian et al. 2005), a network N can be ...