Evaluating adaptation strategies for low resource word sense disambiguation in Oromo using the BERT base multilingual cased model
摘要
The performance of large language models (LLMs) for Oromo Word Sense Disambiguation (WSD) in a low-resource setting is investigated in this work. In addition to zero-shot, few-shot, and comprehensive fine-tuning paradigms, special attention is given to parameter-efficient adaptation methods such as LoRA and MoA+ROSA. MoA+ROSA maintains the same architecture by incorporating ROSA regularization and using the same LoRA backbone (since PEFT does not support mixture-of-adapters).The tests use WordPiece tokenization and [CLS] token embeddings to capture semantic differences across 60 senses in a controlled dataset, utilizing BERT-base-multilingual-cased. A comparative investigation reveals that low-rank adaptation techniques perform poorly in situations of extreme data sparsity, but few-shot and full fine-tuning attain high accuracy and reliable predictions, efficiently improving lexical representations for precise sense identification. Transferring knowledge from high-resource languages to Oromo, a morphologically rich African language, can result in alignment patterns and possible performance loss, according to cross-lingual transfer analyses. Diagnostic indicators, such as variance, bias, and per-class degradation (RelDrop), shed light on the inconsistent performance across senses and the dependability of the model. The tiny dataset size, the poor performance of parameter-efficient adaptations, and the paucity of ablation investigations are some of the limitations that limit our comprehension of component-level contributions. When taken as a whole, the results improve low-resource NLP by showing how contextual embeddings, adaption techniques, and fine-tuning work together resolve sense ambiguity in a low-resource, morphologically rich African language.