ABSTRACT
The social mobility application of the previous chapter can be considered as an example of a network that links the set of occupations. Each element of the table linked two occupations with a certain strength of association according to the number of father-son counts for that occupation pair. In network theory a set of items is linked to items of the same set or to items of a different set by a measure of their relationship. Relationships between two sets of items, or two-mode networks, fit into the general scheme of correspondence analysis (CA) of a rectangular matrix of associations, usually counts. CA is thus a natural methodology for analysing and interpreting two-mode networks. In this chapter we will concentrate on one-mode networks, where the relationships are coded into a square matrix, which presents unique features reminiscent of multidimensional scaling. This square matrix can be either symmetric, for an undirected network, or non-symmetric, for a directed network.
