MoVoC: Morphology-Aware Subword Construction for Ge’ez Script Languages

ACL ARR 2025 May Submission4154 Authors

Abstract: Subword-based tokenization methods often fail to preserve morphological boundaries, a limitation especially pronounced in low-resource, morphologically complex languages such as those written in the Ge‘ez script. To address this, we present MoVoC (Morpheme-aware Subword Vocabulary Construction) and train MoVoC-Tok, a tokenizer that integrates supervised morphological analysis into the subword vocabulary. This hybrid segmentation approach combines morpheme-based and Byte Pair Encoding (BPE) tokens to preserve morphological integrity while maintaining lexical meaning. To tackle resource scarcity, we curate and release manually annotated morpheme data for four Ge‘ez script languages and a morpheme-aware vocabulary for two of them. While the proposed tokenization method does not lead to significant gains in automatic translation quality, we observe consistent improvements in intrinsic metrics, MorphoScore, and Boundary Precision, highlighting the value of morphology-aware segmentation in enhancing linguistic fidelity and token efficiency. Our morpheme-annotated datasets and tokenizer dataset will be publicly available under the Open Data licenses to support further research in low-resource, morphologically rich languages.

Paper Type: Long

Research Area: Resources and Evaluation

Research Area Keywords: Morphological Annotation, Subword Segmentation, Morpheme-Aware Vocabulary

Contribution Types: Data resources

Languages Studied: Amharic, Tigrinya, Ge'ez, Tigre

Submission Number: 4154