10. The method as recited in claim 9 , wherein computing the score for each of the plurality of geographical names comprises: determining one or more frequencies of each geographical name's appearances in the document; assigning one or more positional weights to each geographical name according to positions of the geographical name's appearances in the document; and computing the score of each geographical name based on the one or more frequencies and the one or more positional weights of the respective geographical name.
10. The method as recited in claim 9 , wherein computing the score for each of the plurality of geographical names comprises: determining one or more frequencies of each geographical name's appearances in the document; assigning one or more positional weights to each geographical name according to positions of the geographical name's appearances in the document; and computing the score of each geographical name based on the one or more frequencies and the one or more positional weights of the respective geographical name. 11. The method as recited in claim 10 , wherein assigning one or more positional weights to each geographical name according to positions of the geographical name's appearances in the document comprises: identifying one or more position types where the geographical name appears in the document, the one or more position types including at least one of title, a first paragraph and other paragraphs in the document; and assigning a respective positional weight to each position type where the geographical name appears in the document.