Trivial Transfer Learning for Low-Resource Neural Machine Translation
Table 7: Summary of vocabulary overlaps for the various language sets. All figures in % of the shared vocabulary.
['Languages', 'Unique in a Lang.', 'In All', 'From Parent']
, what portion is shared by all the languages and what portion of subwords benefits from the parent training. We see a similar picture across the board, only AR-RU-ET-EN stands out with the very low number of subwords (6.2%) available already in the parent. The parent AR-RU thus offered very little word knowledge to the child and yet lead to a gain in BLEU.