Understanding Large Temporal Networks and Spatial Networks: Exploration, Pattern Searching, Visualization and Network Evolution

3Methods for Large Networks

The first three temporal networks considered in this book are citation networks. Contemporary citation network analysis has quite old origins. Bernal (1953) and Asimov (1963) provided important foundations. Asimov's The Genetic Code provided a listing of key manuscripts, in one area of science, from which Garfield et al. (1964) extracted citation links between these documents.¹ This idea was the inspiration for a citation network as a concept and for creating citation networks. Asimov's history of DNA was one of a set of demonstration projects for the viability of this approach to studying the history of science. They showed that their analysis was able to achieve a high degree of coincidence between the citation relationships they established between publication events and a historian's account of these events. As they formulated their approach, the basic goal of citation network analysis is to identify the main scientific productions and the main branches or themes in the development of a field. Recent overviews and discussions of approaches to citation network analysis can be found in Lucio-Arias and Leydesdorff (2008) and Calero-Medina and Noyons (2008).

Figure 3.1 shows the small citation network taken from the DNA literature (see Garfield (1979) for details) as drawn by Hummon and Doreian (1989). The years of publication ranged from 1820 to 1962 for important publications regarding the development of DNA theory. Selected decades are marked to ...