This implements the combination method described in
Giuseppe Attardi and Felice Dell'Orletta. 2009. Re-verse revision and linear tree combination for dependency parsing. In Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics, Companion Volume: ShortPapers, pages 261–264, Boulder, Colorado. Association for Computational Linguistics.
If you use this code please also cite the following paper in which experiments using this code are first published.
James Barry, Joachim Wagner and Jennifer Foster. 2020. The ADAPT Enhanced Dependency Parser at the IWPT 2020 Shared Task. In Proceedings of the 16th International Conference on Parsing Technologies and the IWPT 2020 Shared Task on Parsing into Enhanced Universal Dependencies, pages 227–235. Online. Association for Computational Linguistics. DOI: 10.18653/v1/2020.iwpt-1.24
Run combine.py --help for usage.
Footnote 12 of Wagner et al. (2021) Revisiting Tri-training of Dependency Parsers points out that the way how ties are resolved that
occur in the greedy search of the combiner can effect the output quite a lot.
In their work, only three parsers are combined and they resort to running the
combiner multiple times
with different initialisation (option --seed)
and reporting average LAS.