AGGREGATING RESULTS FROM NAMED ENTITY RECOGNITION SERVICES

An aggregation service aggregates extraction results from diverse named entity recognition ("NER") services, which can help improve the quality of extracted information. In some cases, the aggregation service considers differences in entity type classifications when aggregating extraction results from different NER services. The aggregation service can also consider performance characteristics (e.g., error rates) for the different NER services. For example, the aggregation service receives extraction results generated for a document corpus according to an entity type schema for each of multiple different NER services, then aggregates the extraction results based at least in part on relations between entity types for the NER services. For a given annotation area, the computing system can identify hypotheses and rank the hypotheses according to an aggregation approach. For some types of aggregation approach, the computing system uses weight values, error path values and/or other performance characteristics determined during training for the NER services.