By following (Kudo, 2018), we can find the most likely segmentation sequence t starting from all of the n-best segmentations t 1 , • • • ,t n of S(p) rather than from onlyt 1 .
this metric remedies shortcomings of common QAC evaluation metrics, mean reciprocal rank (MRR) and partial-matching MRR (PMRR), which require sampling of a prefix length and are favorable to short queries.