1. A computer-implemented method, comprising: extracting query reformulations from search logs, each of the query reformulations including an initial query and a query qualifier not specified in the initial query; clustering 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; identifying query aspects for the search query from the set of query aspects such that a similarity measure is maximized; and presenting 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.