1. A computer program product for expanding recall, and maintaining precision of a query, the method comprising: a computer readable storage medium having program instructions embodied therewith, wherein the program instructions are executable by a computer processor to cause the computer processor to perform a method comprising: receiving a set of criteria terms of a query comprised of unstructured data; accessing a source of unstructured training data including criteria-relevant terms; generating 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; extracting 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; performing a semantic analysis on the one or more additional terms extracted from the unstructured training data; generating a second set of terms by adding 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; generating 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 generating an expanded recall, and maintaining precision of the query, based on adding the third set of terms to the set of criteria terms of the query.
5. The computer program product of claim 1 , wherein the semantic analysis is performed using a knowledge base of terms related to the set of criteria terms of the query.