Phoenixes at LLMs4OL 2025 Task A: Ontology Learning With Large Language Models Reasoning

Recent advances in large language models (LLMs) have demonstrated remarkable capabilities in various natural language understanding tasks, including Ontology Learning (OL), where they automatically or semi-automatically extract knowledge from unstructured data. This work presents our contribution to the LLMs4OL Challenge at the ISWC 2025 conference, focusing on Task A, which comprises two subtasks: term extraction (SubTask A1) and type extraction (SubTask A2). We evaluate three state-of-the-art LLMs — Qwen2.5-72B-Instruct, Mistral-Small-24B-Instruct-2501, and LLaMA-3.3-70B-Instruct — across three domain-specific datasets: Ecology, Scholarly, and Engineering. In this paper, we adopt a Chain-of-Thought (CoT) Few-Shot Prompting strategy to guide the models in identifying relevant domain terms and assigning their appropriate ontology types. CoT prompting enables LLMs to generate intermediate reasoning steps before producing final predictions, which is particularly beneficial for ontology learning tasks that require contextual reasoning beyond surface-level term matching. Model performance is evaluated using the official precision, recall, and F1-score metrics provided by the challenge organizers. The results reveal important insights into the strengths and limitations of LLMs in ontology learning tasks.