### "Inferring Hierarchical Structure in Networks and Predicting Missing Links" (Next Week at the [Special Summer Bonus] Statistics Seminar)

*Attention conservation notice*: Only of interest if you are
(1) in Pittsburgh next Tuesday, and (2) care
about statistical network
modeling and community discovery. Also, the guest is a friend, collaborator and mentor; but,
despite his undiscriminating taste in acquaintances, an excellent speaker and
scientist.

Usually, during the summer the CMU
statistics seminar finds a shaded corner and drowses through the heat, with
no more activity than an occasional twitch of its tail. Next week, however, it
rouses itself for an exceptional visitor:

- Cristopher Moore, "Inferring Hierarchical Structure in Networks and Predicting Missing Links"
*Abstract*: Given the large amounts of data that are now becoming
available on social and biological networks, we need automated tools to extract
important structural features from this data. Moreoever, for many networks,
observing their links is a costly and imperfect process — food webs
require field work, protein networks require combining pairs of proteins in the
laboratory, and so on. Based on the part of the network we have seen so far,
we would like to make good guesses about what pairs of vertices are likely to
be connected, so we can focus limited resources on those pairs.
- I will present a Bayesian approach to this problem, where we try to infer
the hierarchical structure of the network, with communities and subcommunities
at multiple levels of organization. We start with a rich model of random
networks of this type, and then use a Monte Carlo Markov Chain to explore the
space of these models. This approach performs quite well on real networks,
often outperforming simple heuristics such as assuming that two vertices with
neighbors in common are likely to be connected. In particular, it can handle
both "assortative" behavior like that seen in many social networks, and
"disassortative" behavior as in food webs.
- Joint work with Aaron Clauset and Mark Newman.
*Place and time*: Tuesday, July 13, 2010, 4:00--5:00 p.m. in Porter Hall 125B

As usual, the seminar is free and open to the public.

Networks;
Enigmas of Chance;
Incestuous Amplification

Posted at July 09, 2010 14:33 | permanent link