1. A computer-implemented method of combining text mining services that rely upon different taxonomies, the method comprising: applying a first text mining service relying upon a first taxonomy, to a knowledge base comprising a plurality of documents according to a first iterative instance generation process to generate a plurality of instances of an entity type of the first taxonomy; applying a second text mining service relying upon a second taxonomy, to the knowledge base according to a second iterative instance generation process to generate a plurality of instances of an entity type of the second taxonomy; utilizing the plurality of instances of the first taxonomy and the plurality of instances of the second taxonomy to construct an instance-matching procedure; applying the first text mining service to a target text document smaller than the knowledge base to produce a plurality of first taxonomy entity types; applying the second text mining service to the target text document to produce a plurality of second taxonomy entity types; creating a mapping of the plurality of first taxonomy entity types to the plurality of the second taxonomy entity types based at least in part on the instance-matching procedure; using the mapping to create a merged result that compares a result of applying the first text mining service to the target text document, with a result of applying the second text mining service to the target text document; and displaying the merged result to a user.