1. A method for annotating an entity in a document corpus using cross-document signals, the method comprising: determining which documents in a document corpus mention an entity of interest; clustering the documents that mention the entity of interest according to a temporal signal, a structural signal and/or a content signal, thereby forming at least one cluster of documents; and annotating at least one document in the at least one cluster of documents by marking each occurrence of the entity in the at least one document; wherein at least one of the steps is carried out by a computer device.