15. The system of claim 14 , wherein determining that the term is typographically incorrect comprises determining a synonym quality measure that is a measure of quality of synonym terms that are synonyms of the term does not meet a synonym quality measure threshold.
14. The system of claim 12 , wherein: determining that a term of the original query is a potentially inaccurate term comprises determining that the term is typographically incorrect; and generating one or more derivative queries from the original query comprises generating a derivative query that includes only the terms of the original query that are not the potentially inaccurate term.