1. A method for re-ranking a set of relevant documents identified following a search, the method comprising: determining a set of document content feature values for each relevant document identified; determining one or more of a textual authoritativeness value or a textual authority class for each relevant document using a trained document textual authority model based on the determined set of document content feature values; and rearranging the set of relevant documents in an order selected using at least the determined textual authoritativeness value or the textual authority class for the documents to re-rank the set of relevant documents.