Unlexicalized Transition-basedDiscontinuous Constituency Parsing
Table 6: Morphological analysis results on development sets.
['Corpus', 'Attribute', 'Acc.', 'F1', 'Cov.']
For each morphological attribute, we report an accuracy score computed over every token. However, most morphological attributes are only relevant for specific part-of-speech tags. For instance, tense is only a feature of verbs. The accuracy metric is somewhat misleading, since the fact that the tagger predicts correctly that a token does not have an attribute is considered a correct answer. Therefore, if only 5% of tokens bore a specific morphological attribute, a 95% accuracy is a most-frequent baseline score. For this reason, we also report a coverage metric (Cov.) that indicates the proportion of tokens in the corpus that possess an attribute, and an F1 measure.