Social Network Analysis

Social network analysis (SNA) is both a theoretical perspective and a set of methods. In terms of theory, SNA extends and complements traditional social science by focusing on the causes and consequences of relations between people and among sets of people rather than on the features of individuals. In terms of method, SNA focuses on the measurement of relationships between people. By quantifying the relationships between people, network analysts can apply models and techniques that are commonly used across the social and natural sciences.

Two distinct approaches to SNA arose from two distinct historical traditions. The sociocentric (whole) network approach comes from sociology and was heavily influenced by the work of Georg Simmel. Sociocentric network analysis involves the quantification of relationships between people within a defined group—a classroom of children, a board of directors, the residents of a village or town, the trading partners in a bloc of nations. By representing relationships as numbers, many powerful mathematical and statistical analyses can be applied. Sociocentric network analysis begins with the assumption that members of a group interact more than would a randomly selected group of similar size. The focus is on measuring the structural patterns of those interactions and how those patterns explain outcomes, like the concentration of power or other resources, within the group. Sociocentric network analysts are interested in identifying structural patterns in cases that can be generalized, and in this sense they are like physicists or economists who are interested in modeling behavior.

The egocentric (personal) network approach arose from anthropology and traces its roots to A. R. Rad-cliffe-Brown, among others. This form of SNA is almost always about people rather than about groups. An egocentric network comprises the people (what social network experts call alters) that a person (referred to as ego) knows. An egocentric network thus may have as its members spouses, children, cousins, coworkers, church members, book club members, or just plain friends. The personal network of an elementary school teacher may contain her husband, her son and daughter, all of their friends and relatives, her own friends and relatives, her coworkers, students, parents of students, and members of her church. But she may have more family relations than, for example, the chief executive officer of a large company, who has less time to maintain those relationships.

Egocentric SNA is concerned with making generalizations about the features of personal networks that explain such things as longevity, consumer and voting behavior, coping with difficult life situations, economic success or failure, and so on. With its focus on individuals, the egocentric network approach has been more germane to studies of community than the sociocentric network approach. It is also possible to treat organizations, classrooms, communities, or even nations as the ego in an egocentric network study.