Patent ID: 8156097

Claim:
A search system, comprising: a processing unit; a relevance model receiving a query and identifying information comprising a plurality of retrieved documents relevant to the query using the processing unit; a co-occurrence model, separate from the relevance model, receiving the identified information and identifying a name of one or more persons, not named in the query, having significant knowledge related to subject matter of the query using the processing unit, based on the query and the identified information, the co-occurrence model comprising: a submodel that identifies co-occurrences of the subject matter of the query and a name of a candidate person, not named in the query, in the retrieved documents, and identifies whether the candidate person is related to the subject matter of the query based on the co-occurrences identified, wherein a candidate person who is identified as related to the subject matter of the query is identified as a person having significant knowledge related to the subject matter of the query; a ranking component configured to rank the identified persons based on results from the co-occurrence model; and a re-ranking component configured to: compute a score for each of the identified persons having significant knowledge related to the subject matter of the query based on relationships of the identified person with other ones of the identified persons in the retrieved documents, the relationships being identified based on co-occurrence of the identified person and the other ones of the identified persons in similar subject matter contexts in the retrieved documents, and based on the identified person and the other ones of the identified persons co-occurring in some local contexts in the retrieved documents; and re-rank the identified persons based on the re-ranking component scores and output a re-ranked list.