Cohesion Versus Structural Equivalence as a Basis for Network Subgroups

Two basic approaches to network analysis are compared in terms of the network subgroups each produces. The relational approach, developing from traditional sociometry, focuses on relations between actors (individuals, groups, or corporations) and aggregates actors connected by cohesive bonds into "cliques." The positional approach focuses on the pattern of relations in which an actor is involved and aggregates actors with similar patterns, i.e., "structurally equivalent" actors, into jointly occupied positions. There are several questions that can be posed for a specific project that might lead an individual to analyze subgroups in terms of cohesion versus structural equivalence. Here, considering a series of such questions, I conclude that subgroups based on structural equivalence are to be preferred to those based on cohesion. Cliques can be analyzed as a special type of jointly occupied network position. Illustration is provided by data on the elite experts in methodological and mathematical sociology circa 1975.