Citation network

Egghe & Rousseau (1990, p. 228) explain “when a document d_i cites a document d_j, we can show this by an arrow going from the node representing d_i to the document representing d_j. In this way the documents from a collection D form a directed graph, which is called a ‘citation graph’ or ‘citation network’”. Figure 1. displays such a network, originally published in an article dealing with the problem how to locate articles in the anesthetics field of perturbation of ion transport (Cawkell, 1971). It illustrates the reference connections between nineteen articles published on the subject between 1954 and 1970. It would, however, be unusual if a network of the size of Figure 1. included the entire literature of a subject, but there is no reason why a citation network representing the literature of any subject could not be shown in a similar, larger diagram.

Figure 1. Citation network (Cawkell, 1971, p. 814).

A citation index eases the work of mapping a citation network. In fact, the network in Figure 1. was constructed using the Science Citation Index (SCI) (Cawkell, 1971, p. 814).

Literature:

Cawkell, A. E. (1971). Science Citation Index: Effectiveness in locating articles in the anaesthetics field: ‘Perturbation of ion transport’. British Journal of Anaesthesia, 43: 814.

Egghe, L. & Rousseau, R. (1990). Introduction to Informetrics: Quantitative Methods in Library, Documentation and Information Science. Amsterdam, NL: Elsevier.