Advances in Network Clustering and Blockmodeling

10Blockmodeling Linked Networks

Aleš Žiberna

Faculty of Social Sciences, University of Ljubljana

10.1 Introduction

This chapter introduces the blockmodeling of linked networks. Essentially, it is shown that the multilevel blockmodeling approach [36,38] can also be used for other types of linked networks. The term “linked networks” describes a collection of one-mode networks, where the nodes from different one-mode networks are connected through two-mode networks. While, in principle, all one-mode and two-mode networks can be multi-relational, only single-relational networks are considered in examples. We could also say that linked networks are collections of networks defined on different sets of nodes, where all sets of nodes must somehow be connected. Some examples of linked networks are:

• Multilevel networks Multilevel networks [28] are composed of one-mode networks representing ties among nodes at a given level and two-mode networks that tie nodes from different levels. In a multilevel context, the typical situation has persons as first-level nodes, organizations as second-level nodes, and the two-mode network represents the membership of persons in organizations. Lazega et al. [24] analyzed a multilevel network where the first-level one-mode network had collaboration relations among cancer researchers, the second-level one-mode network had collaboration ties among their research labs, and the two-mode network featured membership of researchers in the labs. The multilevel ...