15. The computer system of claim 9 , wherein a term of the unstructured training data is a phrase comprised of a combination of words and symbols.
9. A computer system for expanding a query, the computer system comprising: one or more computer processors; one or more computer readable storage media; and program instructions stored on the computer readable storage media for execution by at least one of the one or more processors, the program instructions comprising: program instructions to receive a set of criteria terms of a query comprised of unstructured data; program instructions to access a source of unstructured training data including criteria-relevant terms; program instructions to generate a first set of terms from the unstructured training data, by frequency pattern mining of terms meeting or exceeding a pre-determined frequency of occurrence threshold within the unstructured training data; program instructions to extract from the unstructured training data, one or more additional terms in response to a determination that the one or more additional terms fails to match a term of the first set of terms; program instructions to perform a semantic analysis on the one or more additional terms extracted from the unstructured training data; program instructions to a second set of terms by add the one or more additional terms extracted from the unstructured training data to the first set of terms, in response to a determination that the one or more additional terms of the unstructured training data are an inferred match and are semantically related to a term of the set of criteria terms of the query; program instructions to generate a third set of terms, based on removing each term of the second set of terms matching a term of the set of criteria terms of the query; and program instructions to generate an expanded recall, and maintain precision of the query, based on adding the third set of terms to the set of criteria terms of the query.