The co-evolution of socio-technological networks

The modeling of the Internet ecosystem as a whole depends on the
understanding of how the physical, application, and user networks
mutually influence each other and the global processes of information
retrieval, utilization and discovery. We present recent results
obtained in the modeling and analysis of behavioral patterns that
emerge from Internet traffic. First we report on the analysis of flow
data from the Abilene routers that allows the characterization and
functional understanding of user and application-level networks in the
Internet. The second part of the talk tackles specifically the problem
of search engine generated traffic and popularity and show that,
contrary to prior claims and our own intuition, the use of search
engines actually has an egalitarian effect. We reconcile theoretical
arguments with empirical evidence showing that the combination of
retrieval by search engines and search behavior by users mitigates the
attraction of popular pages, directing more traffic toward less
popular sites, even in comparison to what would be expected from users
randomly surfing the Web.

Alessandro Vespignani is Professor of Informatics, Adjunct Professor of
Physics, Professor of Cognitive Science, and Faculty of the
Biocomplexity Institute at Indiana University. His research interests
include complex networks, epidemic modeling and Internet structure. He
is author, together with R. Pastor-Satorras, of the book "evolution and
Structure of the Internet" , published by Cambridge University Press. He
was among the five scientists nominated for the Wired Magazine Rave
Award in science for 2004.

related papers:
S. Fortunato, A.Flammini, F. Menczer and A. Vespignani
Topical interests and the mitigation of search engine bias,
Proc. Natl. Acad. Sci. USA 103, 12684-12689 (2006),
http://www.pnas.org/cgi/content/abstract/103/34/12684

L. Dall'asta, I. Alvarez-Hamelin, A. Barrat, A. Vazquez and A.Vespignani
Exploring networks with traceroute-like probes: theory and simulations
Theoretical Computer Science 355, 6-24 (2006)
http://alexves.googlepages.com/Theocompsci.pdf