Leveraging Data Augmentation for Better Named Entity Recognition in Low-Resource Settings

Abstract

This thesis investigates the challenges in the field of Natural Language Processing (NLP), with a focus on Named Entity Recognition (NER), a subtask within NLP that involves classifying entities. Addressing the issue of data scarcity, which is particularly critical in non-English languages like Swedish, this study investigates various data augmentation methods by fine-tuning the transformer-based model, KB-BERT. The datasets are simulated as low-resource settings, drawing inspiration from the study X Dai and H Adel (2020) [1] work, using three sets of training data containing 50, 150, and 500 instances respectively. The thesis also explores whether a newly developed state-of-the-art data augmentation method can outperform other data augmentation methods in enhancing an NLP model, centering on three data augmentation methods: Synonym replacement, Mention replacement, and AugGPT, the last being a state-of-the-art method. The findings of this study highlight that synonym replacement emerged as the most effective data augmentation method across various low-resource settings, achieving the highest F1-score increase in all scenarios. AugGPT achieved the second highest average F1-score, while mention replacement achieved the lowest across the tested settings.