Discourse Structurein Machine Translation Evaluation
Table 8: Kendall’s (τ) segment level correlation with human judgements on WMT12 obtained by the pairwise preference kernel learning. Results are presented for each language pair and overall.
['[BOLD] Structure', 'cs-en', 'de-en', 'es-en', 'fr-en', 'Overall']
As we can see, the τ scores of the syntactic and the discourse variants are not very different (with a general advantage for syntax), but when put together there is a sizeable improvement in correlation for all the language pairs and overall. This is clear evidence that the discourse-based features are providing additional information, which is not included in syntax.