5. The method of claim 4 , further comprising: collecting a set of supporting evidence passages for the final answer; using passage scorers to form a feature vector for each passage in the set of supporting evidence passages to form a set of feature vectors; and ranking the set of supporting evidence passages for the final answer using the evidence collection multi-instance learned model to form a ranked set of supporting evidence passages.
5. The method of claim 4 , further comprising: collecting a set of supporting evidence passages for the final answer; using passage scorers to form a feature vector for each passage in the set of supporting evidence passages to form a set of feature vectors; and ranking the set of supporting evidence passages for the final answer using the evidence collection multi-instance learned model to form a ranked set of supporting evidence passages. 6. The method of claim 5 , wherein presenting a final answer from the ranked set of answers comprises presenting at least one supporting evidence passage from the ranked set of supporting evidence passages with the final answer.