Rolx: structural role extraction & mining in large graphs

Keith Henderson
Brian Gallagher
Tina Eliassi-Rad
Hanghang Tong
Leman Akoglu
Danai Koutra
Christos Faloutsos
Lei Li
KDD (2012)

Abstract

Given a network, intuitively two nodes belong to the same
role if they have similar structural behavior. Roles should be
automatically determined from the data, and could be, for
example, “clique-members,” “periphery-nodes,” etc. Roles
enable numerous novel and useful network-mining tasks, such
as sense-making, searching for similar nodes, and node classification.
This paper addresses the question: Given a graph,
how can we automatically discover roles for nodes? We
propose RolX (Role eXtraction), a scalable (linear in the
number of edges), unsupervised learning approach for automatically
extracting structural roles from general network
data. We demonstrate the e↵ectiveness of RolX on several
network-mining tasks: from exploratory data analysis
to network transfer learning. Moreover, we compare
network role discovery with network community discovery.
We highlight fundamental di↵erences between the two (e.g.,
roles generalize across disconnected networks, communities
do not); and show that the two approaches are complimentary
in nature.