8. A system comprising: one or more computing devices operable to perform operations comprising: identifying a structured collection of documents, the collection of documents being organized according to a hierarchy of categories, wherein each document is associated with a category; extracting entities from structured collection of documents; assigning language scores to each document in the collection of documents based on one or more language scores for a corresponding category within the hierarchy of categories associated with a respective document, wherein assigning language scores to each document based on language scores for the category includes: determining language scores for a seed category in the hierarchy, and assigning the language scores for the category based on a position of the category within the hierarchy, the language scores for the seed category, and a language score discount based on the distance between the category position and the seed category; assigning one or more language scores to each entity based on scores of associated documents of the collection of documents; and generating a mapping between entities and their assigned language scores.
8. A system comprising: one or more computing devices operable to perform operations comprising: identifying a structured collection of documents, the collection of documents being organized according to a hierarchy of categories, wherein each document is associated with a category; extracting entities from structured collection of documents; assigning language scores to each document in the collection of documents based on one or more language scores for a corresponding category within the hierarchy of categories associated with a respective document, wherein assigning language scores to each document based on language scores for the category includes: determining language scores for a seed category in the hierarchy, and assigning the language scores for the category based on a position of the category within the hierarchy, the language scores for the seed category, and a language score discount based on the distance between the category position and the seed category; assigning one or more language scores to each entity based on scores of associated documents of the collection of documents; and generating a mapping between entities and their assigned language scores. 12. The system of claim 8 , further operable to perform operations comprising: receiving a user input query and matching one or more query terms to one or more entities and using the mapping to determine language scores for the one or more query terms.