14. A computerized searching system configured to: extract, at a computing device, query reformulations from search logs, each of the query reformulations including an initial query and a query qualifier not specified in the initial query; cluster the extracted query reformulations into clusters using modified star clustering such that a set of query aspects is identified, the set of query aspects including query qualifiers of the query reformulations, wherein clustering includes generating star-shaped subgraphs using the query qualifiers, wherein clustering is performed without using the query reformulations or corresponding queries; receiving a search query; identify query aspects for the search query from the set of query aspects such that a similarity measure is maximized; and present the identified query aspects along with results of the search query, wherein the identified query aspects are presented as options for refinement of the search query.
17. The system of claim 14 , wherein each query reformulation comprises an initial query and a subsequent modifier added to the initial query.