1. One or more computer-readable storage media that store executable instructions for determining a text's membership in a class, wherein the instructions, when executed by a computer, cause the computer to perform acts comprising: mapping a plurality of first texts to a concept space, said text being one of said plurality of first texts; training a classifier on a set of labeled examples to identify a boundary, in said concept space, between class membership and class non-membership, wherein said set of labeled examples comprises a first set of points that correspond to texts that are members of said class and a second set of points that are distinct from said first set of points and that correspond to texts that are non-members of said class; using said boundary to identify a region in said concept space that contains non-members of said class, said concept space having n dimensions, said boundary being a hyperplane that has exactly n−1 dimensions and that bifurcates said concept space; identifying one or more second texts that are in said region, said second texts being a subset of said plurality of first texts; and providing, to a user, a tangible result that identifies said one or more second texts.