1. A method comprising: based on a search query, using a computer server system having one or more processors to select a first entry in an index that is stored at a storage device, wherein the first entry is relevant to the search query and comprises a first information item and a first sentence fragment, wherein the first sentence fragment and the first information item are extracted from text of a first electronic document and wherein the first sentence fragment differs from the first information item; generating a search result set comprising at least the first information item of the first entry using the computer server system; and outputting the search result set from the computer server system for use by a client device.
19. The method of claim 1 , wherein: the index comprises a collection of entries that each comprises an information item and a sentence fragment; the information items in the index each comprise one of a date, an entity name, and a concept; and the sentence fragments in the index each comprise factual information related to and found in close proximity in text of an electronic document to the information item in a same entry.