13. At least one computer-readable storage medium encoded with computer-executable instructions that, when executed, perform a method comprising: matching a token from at least a portion of a text string with a matching concept in an ontology; identifying a first concept as being hierarchically related to the matching concept within the ontology; identifying a second concept as being hierarchically related to the first concept within the ontology; including the first and second concepts in a set of features of the token; and determining a measure related to a likelihood that the at least a portion of the text string corresponds to a particular entity type, based at least in part on the set of features of the token.
13. At least one computer-readable storage medium encoded with computer-executable instructions that, when executed, perform a method comprising: matching a token from at least a portion of a text string with a matching concept in an ontology; identifying a first concept as being hierarchically related to the matching concept within the ontology; identifying a second concept as being hierarchically related to the first concept within the ontology; including the first and second concepts in a set of features of the token; and determining a measure related to a likelihood that the at least a portion of the text string corresponds to a particular entity type, based at least in part on the set of features of the token. 19. The at least one computer-readable storage medium of claim 13 , wherein the determining comprises inputting the first and second concepts, as features of the token, to a statistical model trained to determine the measure based on a plurality of features of the token.