The structure of scientific collaboration networks

Abstract

The structure of scientific collaboration networks is investigated. Two scientists are considered connected if they have authored a paper together and explicit networks of such connections are constructed by using data drawn from a number of databases, including MEDLINE (biomedical research), the Los Alamos e-Print Archive (physics), and NCSTRL (computer science). I show that these collaboration networks form "small worlds," in which randomly chosen pairs of scientists are typically separated by only a short path of intermediate acquaintances. I further give results for mean and distribution of numbers of collaborators of authors, demonstrate the presence of clustering in the networks, and highlight a number of apparent differences in the patterns of collaboration between the fields studied.

Figure 1

Histograms of the number of collaborators of scientists in four of the databases studied here. The solid lines are least-squares fits to Eq. 1.

Figure 2

Histograms of the number of papers written by scientists in four of the databases. As with Fig. 1, the solid lines are least-squares fits to Eq. 2.

Figure 3

Average distance between pairs of scientists in the various communities, plotted against the average distance on a random graph of the same size and average coordination number. The dotted line is the best fit to the data that also passes through the origin.