Cross-lingual Dependency Parsing with Unlabeled Auxiliary Languages
Table 7: Average cross-lingual performance difference between the SelfAtt-Graph parser trained on the source (en) and an auxiliary (x) language and the SelfAtt-Graph parser trained only on English (en) language (UAS%/LAS%, excluding punctuation). We use multilingual BERT in this set of experiments.
['Lang', '(en,ru) - en', '(en,fr) - en', '(en,de) - en', '(en,la) - en']
We hypothesis that the auxiliary languages to be more helpful for the target languages in the same family. The experimental results moderately correlate with our expectation. Specifically, the Germanic family benefits the most from employing German (de) as the auxiliary language; similarly Slavic family with Russian (ru) as the auxiliary language (although German as the auxiliary language brings similar improvements). The Romance family is an exception because it benefits the least from using French (fr) as the auxiliary language. This may due to the fact that French is too closed to English, thus is less suitable to be used as an auxiliary language.