68. The computer storage medium of claim 58 , the operations further comprising: in response to a user input indicating that a first attribute suggestion matches the first search query, generating an additional search query that includes the first search query and the first attribute suggestion.
58. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by one or more computers cause the one or more computers to perform operations comprising: determining that a first search query includes a respective text reference to each of one or more predetermined attributes, wherein each attribute is associated with a first entity type; obtaining search results for the first search query from a search engine, each search result identifying a respective resource; for each of a plurality of the obtained search results, determining an initial score for each of a plurality of entities of the first entity type based on occurrences of names of the entity in the resource identified by the search result; generating a final score for each of the plurality of entities based on the initial scores; selecting one or more names of entities of the first entity type to include in a response to the first search query based on the final scores: and generating one or more attribute suggestions to include in the response to the search query, each attribute suggestion identifying a respective additional attribute associated with the first entity type, wherein generating the one or more attribute suggestions comprises: identifying one or more associated attributes for each of the selected entities; and selecting the associated attributes that maximally refine the selected entities as being attribute suggestions.