Findings of the 2016 WMT Shared Taskon Cross-lingual Pronoun Prediction
Table 5: Number of pronouns for the different classes in the IWSLT15 data before and after filtering.
['German–English word', 'German–English before', 'German–English after', 'English–German word', 'English–German before', 'English–German after', 'English–French word', 'English–French before', 'English–French after']
For the automatic filtering, we parsed the data using Mate Tools to perform joint PoS-tagging and dependency parsing. For the ambiguous pronouns, we then removed all pronoun instances that were not labelled as subjects, i.e., had the dependency label SBJ for English or SB for German. For French–English, no filtering was performed since all source pronouns are unambiguous subject pronouns. For all languages, there was a large reduction for the other class. For German–English, there were also large reductions for several other classes. Evaluations carried out after the shared task showed that this was mainly due to the dependency label EP, which marks expletives, and which should not have been filtered away. This mainly affected translation from “es gibt” / “there is”, and explains the large reduction of the there class for German–English.