Towards Better UD Parsing: Deep Contextualized Word Embeddings, Ensemble, and Treebank Concatenation
Table 2: The developement performance with cross-domain concatenation for languages which has multiple treebanks. single means training the parser on it own treebank without concatenation. # train shows the number of training sentences in the treebank measured in thousand.
['[ITALIC] en', 'ewt', 'gum', 'lines', '[ITALIC] fr', 'gsd', 'sequoia', 'spoken']
Numbers of sentences in the training set are also shown in this table. The general trend is that for the treebank with small training set, cross-domain concatenation achieves better performance. While for those with large training set, concatenation does not improve the performance or even worsen the results.