Basic notions for the analysis of large two-mode networks

Many large real-world networks actually have a two-mode nature: their nodes may be separated into two classes, the links being between nodes f different classes only. Despite this, and despite the fact that many ad hoc tools have been designed for the study of special cases, very few exist o analyse (describe, extract relevant information) such networks in a systematic way. We propose here an extension of the most basic notions used owadays to analyse large one-mode networks (the classical case) to the two-mode case. To achieve this, we introduce a set of simple statistics, hich we discuss by comparing their values on a representative set of real-world networks and on their random versions. This makes it possible o evaluate their relevance in capturing properties of interest in two-mode networks. 2007 Elsevier B.V. All rights reserved.