1. A method for characterizing a subject annotation type system according to a reference annotation type system, comprising: providing a reference set of document annotators; providing a set of reference annotation type systems; providing a plurality of documents; annotating each of said plurality of documents using at least one of said reference set of document annotators and said reference annotation type systems to generate a pre-annotated reference document set; annotating said document corpus using said subject annotator and said subject annotation type system to generate a pre-annotated evaluation document set; comparing at least one of said documents in said pre-annotated evaluation document set to its corresponding documents in said pre-annotated reference document set, to generate a matching data representing matches in location, within said compared documents, between instances of annotations in the subject annotation type system and instances of annotations in the reference annotation type systems; and selecting, based on said matching data, a reference document annotation type system that meets a pre-determined correlation criterion with respect to said subject annotation type system.