Kvistur 2.0: a BiLSTM Compound Splitter for Icelandic

Jón Daðason, David Mollberg, Hrafn Loftsson, Kristín Bjarnadóttir


Abstract
In this paper, we present a character-based BiLSTM model for splitting Icelandic compound words, and show how varying amounts of training data affects the performance of the model. Compounding is highly productive in Icelandic, and new compounds are constantly being created. This results in a large number of out-of-vocabulary (OOV) words, negatively impacting the performance of many NLP tools. Our model is trained on a dataset of 2.9 million unique word forms and their constituent structures from the Database of Icelandic Morphology. The model learns how to split compound words into two parts and can be used to derive the constituent structure of any word form. Knowing the constituent structure of a word form makes it possible to generate the optimal split for a given task, e.g., a full split for subword tokenization, or, in the case of part-of-speech tagging, splitting an OOV word until the largest known morphological head is found. The model outperforms other previously published methods when evaluated on a corpus of manually split word forms. This method has been integrated into Kvistur, an Icelandic compound word analyzer.
Anthology ID:
2020.lrec-1.492
Volume:
Proceedings of the Twelfth Language Resources and Evaluation Conference
Month:
May
Year:
2020
Address:
Marseille, France
Editors:
Nicoletta Calzolari, Frédéric Béchet, Philippe Blache, Khalid Choukri, Christopher Cieri, Thierry Declerck, Sara Goggi, Hitoshi Isahara, Bente Maegaard, Joseph Mariani, Hélène Mazo, Asuncion Moreno, Jan Odijk, Stelios Piperidis
Venue:
LREC
SIG:
Publisher:
European Language Resources Association
Note:
Pages:
3991–3995
Language:
English
URL:
https://aclanthology.org/2020.lrec-1.492
DOI:
Bibkey:
Cite (ACL):
Jón Daðason, David Mollberg, Hrafn Loftsson, and Kristín Bjarnadóttir. 2020. Kvistur 2.0: a BiLSTM Compound Splitter for Icelandic. In Proceedings of the Twelfth Language Resources and Evaluation Conference, pages 3991–3995, Marseille, France. European Language Resources Association.
Cite (Informal):
Kvistur 2.0: a BiLSTM Compound Splitter for Icelandic (Daðason et al., LREC 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.lrec-1.492.pdf
Code
 jonfd/kvistur