13. A computer-readable storage device including computer-executable instructions that, when executed by a processor, cause the processor to perform acts including: identifying one or more features of a query; determining, by employing a query classifier, whether the query is intrinsically diverse or not intrinsically diverse based on the one or more features of the query, wherein the query is intrinsically diverse when included in an intrinsically diverse session, wherein the intrinsically diverse session is directed towards a task, and wherein queries included in the intrinsically diverse session are directed towards respective subtasks of the task; receiving search results retrieved by a search engine responsive to executing the query; receiving related queries that correspond to the search results; evaluating an objective function to compute an optimized value when the query is determined to be intrinsically diverse, wherein: the objective function is based on relevance of differing search results to the query, the differing search results returned responsive to the related queries; and the objective function is based on redundancy between the related queries; and controlling presentation of the search results on a display screen according to the optimized value when the query is determined to be intrinsically diverse.
13. A computer-readable storage device including computer-executable instructions that, when executed by a processor, cause the processor to perform acts including: identifying one or more features of a query; determining, by employing a query classifier, whether the query is intrinsically diverse or not intrinsically diverse based on the one or more features of the query, wherein the query is intrinsically diverse when included in an intrinsically diverse session, wherein the intrinsically diverse session is directed towards a task, and wherein queries included in the intrinsically diverse session are directed towards respective subtasks of the task; receiving search results retrieved by a search engine responsive to executing the query; receiving related queries that correspond to the search results; evaluating an objective function to compute an optimized value when the query is determined to be intrinsically diverse, wherein: the objective function is based on relevance of differing search results to the query, the differing search results returned responsive to the related queries; and the objective function is based on redundancy between the related queries; and controlling presentation of the search results on a display screen according to the optimized value when the query is determined to be intrinsically diverse. 20. The computer-readable storage device of claim 13 , the redundancy between the related queries being based on similarities between snippets of the differing search results returned responsive to the related queries.