Social network analysis (SNA) is currently mainly a theme within sociology, but the study of networks has received some attention from other disciplines as well (e.g, physics). Since it is possible to build social networks from empirical data and use software to visualise the results in graphics, it becomes interesting to see if historical data relating to malacologists may be usefully applied with these methods.
An important distinction in SNA is between ‘egocentric social networks’ (hereafter ‘egonets’) and ‘whole social networks’ (hereafter ‘networks’). In the historical context we are interested in, an egonet always takes always the perspective from one person and tries to study his/her relationships. In the case of malacologists thus the relationship between malacologist A (‘ego’) and malacologist B, C, D, etc. (the ‘alter(i)’).
But this figure makes also clear that there may relationships between the alter(i). So one has to define the network boundary, or alternatively one studies a large group (of which the egonet of malacologist A is only a part); this is a ‘whole social network’ (also with a defined boundary, e.g. the European malacologists, which does not mean that alter(i) from outside Europe may not be included; it all depends on the research question).
One example of a question that one could ask is: What flows through the network from one individual to another? In a malacological network e.g., one could make a distinction in the development of contacts between two persons of the following, nested categories: (a) the exchange of questions, ideas or informal knowledge (through correspondence or meetings); (b) the exchange of material (i.c. dry shells or preserved molluscs), and (c) the exchange of formal knowledge (i.c. in publications or through reprints).
 Herz et al., 2016: 4/38.
Herz A, Heidler R, Gamper M, Stark M, Düring M. 2016. Erhebung von Netzwerkdaten. Syllabus 10. Trier Summer School on Social Network Analysis.