The present invention provides a method and system of partitioning authors on a given topic in a newsgroup into two opposite classes of the authors. In an exemplary embodiment, the method and system include identifying all links among the authors, where each link represents a response from one of the authors to another of the authors and analyzing the identified links, where the identified links are assumed to be more likely to be antagonistic links rather than non-antagonistic links. In an exemplary embodiment, the identifying includes assigning a vertex of a graph to each of the authors and assigning an edge of the graph to each interaction between two of the assigned vertices corresponding to two of the authors. In an exemplary embodiment, the analyzing includes solving a min-weight approximately balanced cut problem on a co-citation matrix of the graph, thereby generating the two opposite classes of the authors.