Fast BTG-Forest-Based Hierarchical Sub-sentential Alignment
Table 1: Alignment error rate (AER), wall-clock time (minutes:seconds) required to obtain the symmetric alignments and phrase table size (# of entries) on KFTT corpus.
['[EMPTY]', '[BOLD] AER', '[BOLD] Time', '[BOLD] Size (M)']
AER (Hieralign) is behind fast align, even more than GIZA++. There is no proof that improvements in alignment quality metrics lead to improvements in phrase-based SMT performance. Since our method forces each source and target word aligned (many-to-many), it is prone to generate fewer entries in the translation tables. We thus measured the sizes of the translation tables obtained. Phrase tables extracted from the alignments by Hieralign are smaller by a third in comparison to those of the baseline.