Lemmatisation & Morphological Analysis of Unedited Greek: Do Simple Tasks Need Complex Solutions?

Colin Swaelens, Ilse De Vos, Els Lefever


Abstract
Fine-tuning transformer-based models for part-of-speech tagging of unedited Greek text has outperformed traditional systems. However, when applied to lemmatisation or morphological analysis, fine-tuning has not yet achieved competitive results. This paper explores various approaches to combine morphological features to both reduce label complexity and enhance multi-task training. Specifically, we group three nominal features into a single label, and combine the three most distinctive features of verbs into another unified label. These combined labels are used to fine-tune DBBERT, a BERT model pre-trained on both ancient and modern Greek. Additionally, we experiment with joint training – both among these labels and in combination with POS tagging – within a multi-task framework to improve performance by transferring parameters. To evaluate our models, we use a manually annotated gold standard from the Database of Byzantine Book Epigrams. Our results show a nearly 9 pp. improvement, demonstrating that multi-task learning is a promising approach for linguistic annotation in less standardised corpora.
Anthology ID:
2025.findings-acl.399
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7681–7689
Language:
URL:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.findings-acl.399/
DOI:
Bibkey:
Cite (ACL):
Colin Swaelens, Ilse De Vos, and Els Lefever. 2025. Lemmatisation & Morphological Analysis of Unedited Greek: Do Simple Tasks Need Complex Solutions?. In Findings of the Association for Computational Linguistics: ACL 2025, pages 7681–7689, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Lemmatisation & Morphological Analysis of Unedited Greek: Do Simple Tasks Need Complex Solutions? (Swaelens et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.findings-acl.399.pdf