2. The method claim 1 , wherein identifying the classifier function includes performing a random walk over the web pages by: choosing a starting point in a directed graph having nodes representing the web pages in the collection and edges representing links among the nodes; and repeatedly moving to a new node in the directed graph by selecting uniformly, at random, whether to follow a link from a current node to another node in the directed graph or to randomly jump to another node in the directed graph.
2. The method claim 1 , wherein identifying the classifier function includes performing a random walk over the web pages by: choosing a starting point in a directed graph having nodes representing the web pages in the collection and edges representing links among the nodes; and repeatedly moving to a new node in the directed graph by selecting uniformly, at random, whether to follow a link from a current node to another node in the directed graph or to randomly jump to another node in the directed graph. 6. The method of claim 2 and further comprising: breaking the directed graph into strongly connected components, such that each node in any given strongly connected component has at least one path, through links in the given strongly connected component, to every other node in the given strongly connected component.