Scientific collaboration network is a

social network A social network is a social structure made up of a set of social actors (such as individuals or organizations), sets of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods fo ...

where nodes are scientists and links are co-authorships as the latter is one of the most well documented forms of scientific collaboration. It is an undirected, scale-free network where the degree distribution follows a power law with an exponential cutoff – most authors are sparsely connected while a few authors are intensively connected. The network has an assortative nature – hubs tend to link to other hubs and low-degree nodes tend to link to low-degree nodes.

Assortativity Assortativity, or assortative mixing is a preference for a network's nodes to attach to others that are similar in some way. Though the specific measure of similarity may vary, network theorists often examine assortativity in terms of a node's de ...

is not structural, meaning that it is not a consequence of the degree distribution, but it is generated by some process that governs the network’s evolution.

Study by Mark Newman

A detailed reconstruction of an actual collaboration was made by

Mark Newman Mark Newman is an English-American physicist and Anatol Rapoport Distinguished University Professor of Physics at the University of Michigan, as well as an external faculty member of the Santa Fe Institute. He is known for his fundamental contri ...

. He analyzed the collaboration networks through several large databases in the fields of biology and medicine, physics and computer science in a five-year window (1995-1999). The results showed that these networks form small worlds, in which randomly chosen pairs of scientists are typically separated by only a short path of intermediate acquaintances. They also suggest that the networks are highly clustered, i.e. two scientists are much more likely to have collaborated if they have a third common collaborator than are two scientists chosen randomly from the community.

Prototype of evolving networks

Barabasi et al. studied the collaboration networks in mathematics and neuro-science of an 8-year period (1991-1998) to understand the topological and dynamical laws governing complex networks. They viewed the collaboration network as a prototype of

evolving networks Evolving networks are networks that change as a function of time. They are a natural extension of network science since almost all real world networks evolve over time, either by adding or removing nodes or links over time. Often all of these pr ...

, as it expands by the addition of new nodes (authors) and new links (papers co-authored). The results obtained indicated that the network is scale-free and that its evolution is governed by preferential attachment. Moreover, authors concluded that most quantities used to characterize the network are time dependent. For example, the average degree (network's interconnectedness) increases in time. Furthermore, the study showed that the node separation decreases over time, however this trend is believed to be offered by incomplete database and it can be opposite in the full system.

References

{{Reflist, 2 Social networks