Systems and methods for authoritativeness grading, estimation and sorting of documents in large heterogeneous document collections

Systems and methods for determining the authoritativeness of a document based on textual, non-topical cues. The authoritativeness of a document is determined by evaluating a set of document content features contained within each document to determine a set of document content feature values, processing the set of document content feature values through a trained document textual authority model, and determining a textual authoritativeness value and/or textual authority class for each document evaluated using the predictive models included in the trained document textual authority model. Estimates of a document's textual authoritativeness value and/or textual authority class can be used to re-rank documents previously retrieved by a search, to expand and improve document query searches, to provide a more complete and robust determination of a document's authoritativeness, and to improve the aggregation of rank-ordered lists with numerically-ordered lists.