Both sources are presented in triples, argument 1 -predicate-argument 2 , (e.g., Gates-create-Microsoft), where the two arguments are usually entities and the predicate is the relation between them (Zhang et al., 2014).
knowledge selection For each document d, we then select the subset of relevant knowledge instances, in the sense that they represent relations between the entities in d. we extract all entities in d, and query the knowledge bases to obtain all the knowledge instances in which both of the two arguments, argument 1 and argument 2 , match some of the entities in d. One issue in knowledge selection is whether to retrieve knowledge instances using exact or partial matching.