1. A computer-implemented method of searching for information, comprising: at a server system: receiving from a client system a fill-the-blank query comprising one or more term segments and one or more missing term identifiers signifying missing information sought by a user; converting the fill-the-blank query into a corresponding search pattern, wherein the search pattern includes: one or more missing content identifiers corresponding to the one or more missing term identifiers, and a set of one or more query expressions corresponding to each term segment; identifying a set of documents matching the search pattern; identifying content in the set of documents corresponding to the search pattern, the identified content including one or more potential answers corresponding to the one or more missing term identifiers; and responding to the query by providing to the client system at least one of the one or more potential answers.