1. A computer-implemented method for associating a category to a set of nodes of a graph, the computer-implemented method comprising: determining a first node representing a first term that matches the category; locating a second node associated with the first node based at least in part on a degree of cross-reference, the second node representing a second term; determining whether the degree of cross-reference satisfies a threshold; in response to determining that the degree of cross-reference satisfies the threshold, storing, on a volatile or non-volatile computer-readable storage medium, information that indicates an association between the second term and the category.