NITK-VITAL at SemEval-2025 Task 11: Focal-RoBERTa: Addressing Class Imbalance in Multi-Label Emotion Classification

AbstractThis paper presents our approach to SemEval Task 11, which focuses on multi-label emotion detection in English textual data. We experimented with multiple methodologies, including traditional machine learning models, deep learning architectures, and transformer-based models. Our best-performing approach employed RoBERTa with focal loss, which effectively mitigated class imbalances and achieved a macro F1-score of 0.7563, outperforming other techniques. Comparative analyses between different embedding strategies, such as TF-IDF, BERT, and MiniLM, revealed that transformer-based models consistently provided superior performance. The results demonstrate the effectiveness of focal loss in handling highly skewed emotion distributions. Our system contributes to advancing multi-label emotion detection by leveraging robust pre-trained models and loss function optimization.