The structure of scientific collaboration networks

The structure of scientific collaboration networks is investigated. Two sci entists 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 Lo s Alamos e-Print Archive (physics), and NCSTRL (computer science). I show t hat these collaboration networks form "small worlds," in which randomly cho sen pairs of scientists are typically separated by only a short path of int ermediate acquaintances. I further give results for mean and distribution o f numbers of collaborators of authors, demonstrate the presence of clusteri ng in the networks, and highlight a number of apparent differences in the p atterns of collaboration between the fields studied.