The LMU Munich System for the WMT20 Very Low Resource Supervised MT Task

Jindřich Libovický, Viktor Hangya, Helmut Schmid, Alexander Fraser

WMT 2020

We present our systems for the WMT20 Very Low Resource MT Task for
translation between German and Upper Sorbian. For training our
systems, we generate synthetic data by both backand
forward-translation. Additionally, we enrich the training data with
German-Czech translated from Czech to Upper Sorbian by an
unsupervised statistical MT system incorporating orthographically
similar word pairs and transliterations of OOV words.  Our best
translation system between German and Sorbian is based on transfer
learning from a Czech-German system and scores 12 to 13 BLEU higher
than a baseline system built using the available parallel data only.