1. A method to analyze a plurality of candidate answers for a case received by a question answering system, the method comprising: defining a first set of a plurality of features for: (i) the candidate answers, and (ii) a plurality of items of evidence, wherein defining the first set of features further specifies to merge the first set of features of the plurality of items of evidence based on a set of attributes of each feature in the first set of features; defining a second set of the plurality of features, different than the first set of features, wherein defining the second set of features further specifies to merge the second set of features of the plurality of items of evidence based on a set of attributes of each feature in the second set of features; computing a first feature score for the merged first set of features for each of the plurality of items of evidence for a first candidate answer of the plurality of candidate answers, wherein the first feature score is based on the set of attributes of each feature in the first set of features and each feature in the merged first set of features of the plurality of items of evidence, wherein the first feature score, the set of attributes of each feature in the first set of features, and the merged first set of features of the plurality of items of evidence are related to a first attribute of a plurality of attributes of the plurality of candidate answers and the plurality of items of evidence; computing a second feature score for the merged second set of features for the plurality of items of evidence for the first candidate answer, wherein the second feature score is based on: (i) the set of attributes of each feature in the second set of features, (ii) the first feature score for the merged first set of features for the respective item of evidence, and (iii) each feature in the merged second set of features of the plurality of items of evidence, wherein the second feature score, the set of attributes of each feature in the second set of features, and the merged second set of features of the plurality of items of evidence are related to a second attribute of the plurality of attributes; selecting a first merging technique, from a plurality of merging techniques, for merging the first and second feature scores; and computing a merged feature score for the first candidate answer based on the first merging technique applied to the first and second feature scores for each of the plurality of items of evidence.