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Betweenness Centrality as a Driver of Preferential Attachment 
in the Evolution of Research Collaboration Networks
< at http://arxiv.org/abs/1111.6804 >

Alireza Abbasi, Liaquat Hossain, and Loet Leydesdorff

We analyze whether preferential attachment in scientific coauthorship
networks is different for authors with different forms of centrality. Using
a complete database for the scientific specialty of research about "steel
structures," we show that betweenness centrality of an existing node is a
significantly better predictor of preferential attachment by new entrants
than degree or closeness centrality. During the growth of a network,
preferential attachment shifts from (local) degree centrality to betweenness
centrality as a global measure. An interpretation is that supervisors of PhD
projects and postdocs broker between new entrants and the already existing
network, and thus become focal to preferential attachment. Because of this
mediation, scholarly networks can be expected to develop differently from
networks which are predicated on preferential attachment to nodes with high
degree centrality. 

Alireza Abbasi, Liaquat Hossain
Centre for Complex Systems Research, 
Faculty of Engineering and IT, University of Sydney, 
Sydney, NSW 2006, Australia; [log in to unmask]

Loet Leydesdorff 
Amsterdam School of Communications Research (ASCoR)
Kloveniersburgwal 48, 1012 CX Amsterdam;
[log in to unmask] ; http://www.leydesdorff.net/ 

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