8. A computer system for generating a multi-document summary, the computer system comprising: one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage media, and program instructions stored on at least one of the one or more tangible storage media for execution by at least one of the one or more processors via at least one of the one or more memories, wherein the computer system is capable of performing a method comprising: receiving a query statement, one or more documents, one or more summary constraints, and one or more goals; identifying one or more keywords within the query statement; performing a sentence selection from the one or more documents based on the one or more identified keywords; generating a plurality of candidate summaries of the one or more documents based on the performed sentence selection, the one or more goals, and a fully-polynomial randomized approximation scheme (FPRAS) cross entropy method; calculating a quality score for each of the plurality of generated candidate summaries using a plurality of quality features; and selecting a candidate summary from the plurality of generated candidate summaries with the highest calculated quality score that also satisfies a quality score threshold.
8. A computer system for generating a multi-document summary, the computer system comprising: one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage media, and program instructions stored on at least one of the one or more tangible storage media for execution by at least one of the one or more processors via at least one of the one or more memories, wherein the computer system is capable of performing a method comprising: receiving a query statement, one or more documents, one or more summary constraints, and one or more goals; identifying one or more keywords within the query statement; performing a sentence selection from the one or more documents based on the one or more identified keywords; generating a plurality of candidate summaries of the one or more documents based on the performed sentence selection, the one or more goals, and a fully-polynomial randomized approximation scheme (FPRAS) cross entropy method; calculating a quality score for each of the plurality of generated candidate summaries using a plurality of quality features; and selecting a candidate summary from the plurality of generated candidate summaries with the highest calculated quality score that also satisfies a quality score threshold. 14. The computer system of claim 8 , further comprising: removing one or more candidate summaries from the plurality of generated candidate summaries that do not satisfy the one or more summary constraints.