Closer through commonality: Enhancing hypergraph contrastive learning with shared groups

Hypergraphs provide a superior modeling framework for representing complex multidimensional relationships in the context of real-world interactions that often occur in groups, overcoming the limitations of traditional homogeneous graphs. However, there have been few studies on hypergraphbased contrastive learning, and existing graph-based contrastive learning methods have not been able to fully exploit the highorder correlation information in hypergraphs. Here, we propose a Hypergraph Fine-grained contrastive learning (HyFi) method designed to exploit the complex high-dimensional information inherent in hypergraphs. While avoiding traditional graph augmentation methods that corrupt the hypergraph topology, the proposed method provides a simple and efficient learning augmentation function by adding noise to node features. Furthermore, we expands beyond the traditional dichotomous relationship between positive and negative samples in contrastive learning by introducing a new relationship of weak positives. It demonstrates the importance of fine-graining positive samples in contrastive learning. Therefore, HyFi is able to produce highquality embeddings, and outperforms both supervised and unsupervised baselines in average rank on node classification across 10 datasets. Our approach effectively exploits high-dimensional hypergraph information, shows significant improvement over existing graph-based contrastive learning methods, and is efficient in terms of training speed and GPU memory cost. The source code is available at https://github.com/Noverse0/HyFi.git.

Beyond Right and Wrong: Mitigating Cold Start in Knowledge Tracing Using Large Language Model and Option Weight

Knowledge Tracing (KT) is vital in educational data mining, enabling personalized learning by tracking learners' knowledge states and forecasting their academic outcomes. This study introduces the LOKT (Large Language Model Option-weighted Knowledge Tracing) model to address the cold start problem where limited historical data available using large language models (LLMs). While traditional KT models have incorporated option weights, our research extends this by integrating these weights into an LLM-based KT framework. Moving beyond the binary classification of correct and incorrect responses, we emphasize that different types of incorrect answers offer valuable insights into a learner's knowledge state. By converting these responses into text-based ordinal categories, we enable LLMs to assess learner understanding with greater clarity, although our approach focuses on the final knowledge state rather than the progression of learning over time. Using five public datasets, we demonstrate that the LOKT model sustains high predictive accuracy even with limited data, effectively addressing both "learner cold-start" and "system cold-start" scenarios. These findings showcase LOKT's potential to enhance LLM-based learning tools and support early-stage personalization.