Blockmodels : Interpretation and evaluation

Many methods for the description of social network structural properties are concerned with the dual notions of social position and social role. Common goals of these methods are to represent patterns in complex social network data in simplified form, to reveal sets of actors who are similarly embedded in networks of relations, and to describe the associations among relations in multirelational social networks. Often these representations take the form of a blockmodel. In a blockmodel actors are assigned to positions and network relations are presented among positions, rather than among actors, The literature on blockmodels is extensive and is overflowing with computation and applications of blockmodels. However, there is a surprising lack of attention to two very important aspects of blockmodel analyses: the interpretation and evaluation of the results. The purpose of this paper is to focus on these topics, primarily reviewing and synthesizing the approaches to interpretation and evaluation currently in use.