12. A method according to claim 8 , further comprising: assigning a primary status to those clusters that are larger than a minimum size; assigning a secondary status to the clusters that are smaller than the minimum size; and presenting the primary and secondary clusters.
8. A method for clustering nodes of a tree structure, comprising: maintaining a plurality of messages, each message represented as a node in a tree structure; assigning a word vector to each message; identifying pairs of the nodes based on relationships in the tree structure and combining the nodes of one or more of the pairs into clusters; adjusting boundaries of each cluster, comprising at least one of: placing a root node into one such cluster having a closest related child node; separating children nodes into distinct groups and retaining a relationship between a parent node and one such group comprising a nearest child node; and transferring a parent node to one such cluster having all children of the parent node; and forming a digest of the messages comprising one or more of the clusters.