Tree-to-Sequence Attentional Neural Machine Translation
Table 4: Effects of the Beam Search (BS) on the development data.
['[EMPTY]', 'Beam size', 'RIBES', 'BLEU (BP)']
The beam size is set to 6 or 20 in the simple beam search, and to 20 in our proposed search. We can see that our proposed search outperforms the simple beam search in both scores. Unlike RIBES, the BLEU score is sensitive to the beam size and becomes lower as the beam size increases. We found that the BP had a relatively large impact on the BLEU score in the simple beam search as the beam size increased. Our search method works better than the simple beam search by keeping long sentences in the candidates with a large beam size.