Cross-Lingual Morphological Tagging for Low-Resource Languages
Table 5: Cross-lingual tagging results (F1 scores) per language and per attribute (not showing POS and a small number of attribute types that only appear with 1 or 2 language pairs), for Wsabie projected with type constraints. English and best source language.
['Target Source', 'bg en', 'bg da', 'cs en', 'cs it', 'da en', 'da sv', 'es en', 'es it', 'fi en', 'fi sv', 'it en', 'it pt', 'nl en', 'nl en', 'pl en', 'pl nl', 'pt en', 'pt it', 'sl en', 'sl cs', 'sv en', 'sv da']
We see that there are large differences in accuracy across attributes and across languages. In some cases, the transfer is unsuccessful. For example, degree accuracy in Italian is 2% F1 when projecting from English and 14% F1 projecting from Portuguese. Some of the cases can be explained by differences in where an attribute is marked: For example, for definiteness the performance is 1% from English to Bulgarian, as Bulgarian marks definiteness on nouns and adjectives rather than on determiners. Other attributes are very language-dependent. Gender transfers well between Romance languages, but poorly when transferring from English.