27. The query expander of claim 26, wherein the statistical knowledge base is generated by operation on a restricted training corpus to generate statistical knowledge about the words of the training corpus for storage in the statistical knowledge base.
27. The query expander of claim 26, wherein the statistical knowledge base is generated by operation on a restricted training corpus to generate statistical knowledge about the words of the training corpus for storage in the statistical knowledge base. 28. The query expander of claim 27, wherein the derivational generator includes a set of transducers for producing derivatives of each word of the disambiguated query.