8. A machine-readable hardware storage medium comprising instructions that, when executed by one or more processors of a machine, cause the machine to perform operations comprising: collecting a plurality of user search queries for a product; parsing the collected user search queries to determine one or more aspect phrases for the product, the aspect phrases qualifying the product; identifying aspect metadata for the aspect phrases, the aspect metadata indicating one or more query phrase types of the aspect phrases; creating, from the aspect metadata, a list of aspects for a user query; assigning weights to the list of aspects according to usage of the aspects in the user search queries; receiving the user query and producing ranked search results using the list of aspects; and re-ranking the ranked search results using diversified aspects based on the query phrase type(s) from the ranked index list of aspects to produce user search results.
8. A machine-readable hardware storage medium comprising instructions that, when executed by one or more processors of a machine, cause the machine to perform operations comprising: collecting a plurality of user search queries for a product; parsing the collected user search queries to determine one or more aspect phrases for the product, the aspect phrases qualifying the product; identifying aspect metadata for the aspect phrases, the aspect metadata indicating one or more query phrase types of the aspect phrases; creating, from the aspect metadata, a list of aspects for a user query; assigning weights to the list of aspects according to usage of the aspects in the user search queries; receiving the user query and producing ranked search results using the list of aspects; and re-ranking the ranked search results using diversified aspects based on the query phrase type(s) from the ranked index list of aspects to produce user search results. 13. The machine-readable hardware storage medium of claim 8 , wherein re-ranking the search results comprises using a diversified list of values for the most highly correlated k identified important aspects, k being an integer.