Sociologists working in the area of social network analysis rely on
centrality metrics (e.g., degree, closeness, and betweenness)
to rank individuals in a society according to their power, prestige,
and prominence. To evaluate these metrics, social networks are
represented by graphs: specifically, individuals are represented as
nodes, and the fact that individual A respects individual B is
represented by a link from the node representing A to the node
representing B.
Recently, computer scientists have applied this same abstraction to
compute the ``importance'' of a web page based on the Web's underlying
topology. Just as the power, prestige, and prominence of individuals
in a society is measured in terms of the respect they are granted by
others, the significance of web pages can be measured in terms of the
references they receive from others. The most prominent application
of this idea is the PageRank algorithm, upon which the Google search
engine is built.
At Brown, we are investigating efficient methods of link analysis that
are applicable to large-scale networks with inherent hierarchical
structure: for example, the Web. Our techniques rely on extensions to
the theory of stochastic stability, which we are presently developing.
The technology we are building is not only of interest in the realm of
social network analysis, but it is potentially useful in any field
where the theory of Markov chains is applied, most notably equilibrium
selection in game theory.