Improving Aspect-Based Sentiment Analysis through Large Language Models

Aspect-Based Sentiment Analysis (ABSA) is a crucial task in Natural Language Processing (NLP) that seeks to extract sentiments associated with specific aspects within text data. While traditional sentiment analysis offers a broad view, ABSA provides a fine-grained approach by identifying sentiments tied to particular aspects, enabling deeper insights into user opinions across diverse domains. Despite improvements in NLP, accurately capturing aspect-specific sentiments, especially in complex and multi-aspect sentences, remains challenging due to the nuanced dependencies and variations in sentiment expression. Additionally, languages with limited annotated datasets, such as Arabic, present further obstacles in ABSA. This dissertation addresses these challenges by proposing methodologies that enhance ABSA capabilities through large language models and transformer architectures. Three primary approaches are developed and evaluated: First, aspect-specific sentiment classification using GPT-4 with prompt engineering to improve few-shot learning and in-context classification; second, triplet extraction utilizing an encoder-decoder framework based on the T5 model, designed to capture aspect-opinion-sentiment associations effectively; and lastly, Aspect-Aware Conditional BERT, an extension of AraBERT, incorporating a customized attention mechanism to dynamically adjust focus based on target aspects, particularly improving ABSA in multi-aspect Arabic text. Our experimental results demonstrate that these proposed methods outperform current baselines across multiple datasets, particularly in improving sentiment accuracy and aspect relevance. This research contributes new model architectures and techniques that enhance ABSA for high-resource and low-resource languages, offering a scalable solution adaptable to various domains.