14. The method of claim 13 , further comprising automatically determining whether to reorganize the concept hierarchy in response to detecting addition of a new document to the document corpus.
13. A method comprising: receiving a concept hierarchy at a computing device, wherein the concept hierarchy identifies concepts associated with a document corpus, wherein newly created documents are without user intervention added to the document corpus and deleted documents are without user intervention removed from the document corpus based on information from one or more monitoring agents; generating an interface using the concept hierarchy, wherein the interface is operable to navigate and search the concept hierarchy; receiving a search query via the interface; in response to receiving the search query, identifying document search results by searching the document corpus based on the search query and identifying conceptual search results by searching the concept hierarchy for one or more concepts that are semantically related to the search query; concurrently displaying the document search results and the conceptual search results at the interface, wherein the document search results are selectable via the interface to view one or more documents of the document corpus that are associated with the document search results, and wherein the conceptual search results are selectable via the interface to navigate the concept hierarchy and to view one or more documents of the document corpus that are associated with the conceptual search results.