15. A computer program product stored in a computer readable storage medium, comprising computer program code that, when executed by an information handling system, causes the information handling system to perform actions comprising: identifying an amount of instances of a first entity and a second entity co-occurring within a set of documents, wherein the set of documents correspond to a time duration; determining whether the amount of instances exceeds a threshold; in response to determining that the amount of instances exceeds the threshold, identifying at least one title, corresponding to the set of documents, that comprises the first entity, the second entity, and at least one connecting verb that grammatically connects the first entity to the second entity; in response to identifying the at least one title that comprises the first entity, the second entity, and at least one connecting verb, identifying a plurality of connecting verbs within the set of documents that each grammatically connects the first entity to the second entity, wherein the at least one connecting verb is included in the plurality of connecting verbs; in response to identifying the plurality of connecting verbs, selecting a plurality of document segments within the set of documents that comprise the first entity, the second entity, and at least one of the plurality of connecting verbs; storing the selected plurality of document segments in the memory; and training a relation-based classifier using the stored plurality of document segments.
16. The computer program product of claim 15 wherein the first entity is a first entity type and the second entity is a second entity type, and wherein both the first entity and the second entity are devoid of an entity name.