Abstract: A system and method disambiguates between an incorrectly recognized spoken query and a correctly recognized spoken query for which there are no currently available documents in a database. The method generates a list of unavailable categories of documents. The method also generates surrogate documents that include query terms similar to the categories of unavailable documents. Each surrogate documents also includes a description that indicates why the document is not available. The surrogate documents are included in the database along with the available documents. Spoken queries are matched against all documents in the database including the surrogate documents. If a surrogate document is retrieved, then the user is presented with the description that describes why that category of documents is not available.

Abstract: A method indexes and retrieves documents stored in a database. A document feature vector is extracted from each document and the documents are then indexed according to the feature vectors. A spoken query is converted to an intermediate representation representing likelihoods of possible sequential combinations of terms in the spoken query. A query certainty vector is generated from the intermediate representation. Other information is acquired. The other information is combined with the query certainty vector. The query vector and the other information are then compared to each of the document feature vectors to retrieve a ranked result set of documents.