27. A computer implemented method of responding to a search query made to a fact repository, performed at a computer system having one or more processors and memory storing one or more programs for execution by the one or more processors, the method comprising: receiving the search query; retrieving an annotation value that matches at least a part of the query, wherein an annotation includes additional information about a fact, and wherein the annotation value is indexed to a substring of a fact's value; retrieving at least one fact from the fact repository, the at least one fact corresponding to the received search query and having an attribute and a value, wherein the fact repository includes a plurality of facts associated with objects, wherein a respective fact in the fact repository includes a respective attribute and a respective value, wherein the respective value is a text string, and wherein the plurality of facts are extracted from a plurality of documents; determining whether the at least one fact's value corresponds to the annotation value; and sending the at least one fact in response to the query in accordance with a determination that the at least one fact's value corresponds to the annotation value.
27. A computer implemented method of responding to a search query made to a fact repository, performed at a computer system having one or more processors and memory storing one or more programs for execution by the one or more processors, the method comprising: receiving the search query; retrieving an annotation value that matches at least a part of the query, wherein an annotation includes additional information about a fact, and wherein the annotation value is indexed to a substring of a fact's value; retrieving at least one fact from the fact repository, the at least one fact corresponding to the received search query and having an attribute and a value, wherein the fact repository includes a plurality of facts associated with objects, wherein a respective fact in the fact repository includes a respective attribute and a respective value, wherein the respective value is a text string, and wherein the plurality of facts are extracted from a plurality of documents; determining whether the at least one fact's value corresponds to the annotation value; and sending the at least one fact in response to the query in accordance with a determination that the at least one fact's value corresponds to the annotation value. 28. The method of claim 27 , further comprising returning the retrieved annotation value in response to the query.