Turkish Treebanking - Unifying and Constructing Efforts.

In this paper, we present the re-annotation of the Turkish PUD Treebank and the first annotation of the Turkish National Corpus Universal Dependency (henceforth TNC-UD) Treebank as part of our efforts for unifying and extending the Turkish universal dependency treebanks. In accordance with the Universal Dependencies' guidelines and the necessities of Turkish grammar, both treebanks, the Turkish PUD Treebank and TNC-UD, were revised with regards to their syntactic relations. The TNC-UD is planned to have 10,000 sentences. In this paper, we present the first 500 sentences along with the re-annotation of the PUD Treebank. Moreover, this paper also offers the parsing results of a graph-based neural parser on the previous and re-annotated PUD, as well as the TNC-UD. In light of the comparisons, even though we observe a slight decrease in the attachment scores of the Turkish PUD treebank, we demonstrate that the annotation of the TNC-UD improves the parsing accuracy of Turkish. In addition to the treebanks, we have also constructed a custom annotation software with advanced filtering and morphological editing options. Both of the treebanks, including a full edit-history and the annotation guidelines, as well as the custom software are publicly available online under an open license.