14. A volatile or non-volatile computer-readable non-transitory storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform: presenting, to a querier, a single interface that includes two mechanisms for specifying search terms for the same query in two different manners; wherein the first mechanism includes first controls for receiving a query string from the querier; wherein the second mechanism includes second controls for selecting one of a plurality of selectable items; wherein each selectable item of the plurality of selectable items corresponds to a filter record of a plurality of filter records; wherein said first controls allow the querier to enter one or more search terms that comprise the query string; wherein said second controls allow the querier to specify which filter record, of the plurality of filter records, to use to generate an amended query string based on said query string; receiving a request from the querier, wherein receiving said request includes receiving a first set of search terms from the querier through said first controls and receiving, through said second controls, a selection of a selectable item; based on the request indicating the selection of the selectable item, determining that a selected filter record should be used to process the request, wherein the selected filter record corresponds to the selectable item that was selected through said second controls and includes a set of filter elements that correspond to a second set of search terms; adding search terms that correspond to the filter elements associated with the selected filter record to the first set of search terms to generate said amended query string that includes both the first set of search terms and the second set of search terms; and performing a document-corpus search of a document-corpus by treating the second set of search terms as if they were a part of said first set of search terms submitted through said first controls, to identify a set of documents relevant to the both the first set of search terms and the second set of search terms; wherein performing the document-corpus search involves comparing both the first set of search terms and the second set of search terms to terms contained in documents that belong to the document-corpus.
14. A volatile or non-volatile computer-readable non-transitory storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform: presenting, to a querier, a single interface that includes two mechanisms for specifying search terms for the same query in two different manners; wherein the first mechanism includes first controls for receiving a query string from the querier; wherein the second mechanism includes second controls for selecting one of a plurality of selectable items; wherein each selectable item of the plurality of selectable items corresponds to a filter record of a plurality of filter records; wherein said first controls allow the querier to enter one or more search terms that comprise the query string; wherein said second controls allow the querier to specify which filter record, of the plurality of filter records, to use to generate an amended query string based on said query string; receiving a request from the querier, wherein receiving said request includes receiving a first set of search terms from the querier through said first controls and receiving, through said second controls, a selection of a selectable item; based on the request indicating the selection of the selectable item, determining that a selected filter record should be used to process the request, wherein the selected filter record corresponds to the selectable item that was selected through said second controls and includes a set of filter elements that correspond to a second set of search terms; adding search terms that correspond to the filter elements associated with the selected filter record to the first set of search terms to generate said amended query string that includes both the first set of search terms and the second set of search terms; and performing a document-corpus search of a document-corpus by treating the second set of search terms as if they were a part of said first set of search terms submitted through said first controls, to identify a set of documents relevant to the both the first set of search terms and the second set of search terms; wherein performing the document-corpus search involves comparing both the first set of search terms and the second set of search terms to terms contained in documents that belong to the document-corpus. 17. A volatile or non-volatile computer-readable non-transitory storage medium of claim 14 , further comprising: generating one or more custom filter records based on information extracted from a user profile of the querier; storing, in a filter-record database, the one or more custom filter records; selecting, from the filter-record database, at least one custom filter record of the one or more custom filter records to present to the querier based on information associated with the querier; wherein at least one of the plurality of selectable items corresponds to the at least one custom filter record.