Patent ID: 8606565

Claim:
A related-word registration device comprising: a related-word candidate group generating means that generates a related-word candidate group by extracting candidates of a related word on the basis of a predetermined condition from a search query log in which logs regarding a search query are stored; a receiving means that receives a search query of a search word entered by the user; a partial character string generating means that generates a partial character string from a character string of the search word; a candidate character string extracting means that extracts a candidate character string from the related-word candidate group on the basis of the generated partial character string; a score calculating means that calculates a suitability score of the candidate character string on the basis of similarity between the candidate character string and the search word, the number of use times of the candidate character string, and the number of search results of the search of the candidate character string; a ranking means that ranks the candidate character strings in order of the scores; a criterion generating means that generates a reference line of a suitability score for the ranking as a criterion of determining whether the candidate character string is registered as a related word or not on the basis of the suitability score and the ranking of the candidate character string; a registration character string extracting means that extracts, as a registration character string to be registered as a related word, a candidate character string whose suitability score is apart from the reference line by a preset threshold or larger; and a related-word registering means that registers the extracted registration character string and the search word as related words into a related-word database, wherein the partial character string generating means sets at least one of length of the partial character string and shift width of the number of characters of a search word at the time of generating the partial character string on the basis of the number of characters of the search word, and generates at least one of a partial character string having the set length and a partial character string with the set shift width.