Enumeration of Extractive Oracle Summaries
Table 7: Median number of summaries checked by each search method
['[EMPTY]', 'Rouge1 Naive', 'Rouge1 Proposed', 'Rouge2 Naive', 'Rouge2 Proposed']
The differences in the number of feasible solutions between \sc Rouge1 and \sc Rouge2 are very large. Input set (|D|) of \sc Rouge1 is much larger than \sc Rouge1. On the other hand, the differences between \sc Rouge1 and \sc Rouge2 in our method are of the order of 10 to 102. When comparing our method with naive exhaustive searches, its search space is significantly smaller. The differences are of the order of 107 to 1030 with \sc Rouge1 and 104 to 1017 with \sc Rouge2. These results demonstrate the efficiency of our branch and bound technique.