(1997) noted, it is fairly common for one of the mentions of an entity in a document to be a long, typical surface form of that entity (e.g., "George W. Bush"), while the other mentions are shorter surface forms (e.g., "Bush").
before attempting to solve the semantic ambiguity, the system hypothesizes in-document coreferences and maps short surface forms to longer surface forms with the same dominant label (for example, "Brown"/ PERSON can be mapped to "Michael Brown"/ PERSON ).