Adaptive Retrieval Strategies for Biomedical Question Answering
For biomedical QA researchers, this work addresses the limitation of one-size-fits-all retrieval by demonstrating that question-type-aware strategies can enhance performance, though the gains are incremental.
Biomedical QA systems typically use a unified retrieval pipeline for all question types, which may be suboptimal. The authors propose an adaptive retrieval framework that selects strategies based on question type, improving evidence relevance and answer quality on the BioASQ benchmark.
Biomedical question answering (QA) encompasses diverse question types, including yes/no, factoid, list, and summary questions, each requiring distinct forms of evidence and reasoning. However, most retrieval-augmented QA systems rely on a unified retrieval pipeline, regardless of the information needs of different question categories. This one-size-fits-all approach may limit the effectiveness of evidence acquisition and downstream answer generation. In this work, we propose an adaptive retrieval framework that selects retrieval and evidence aggregation strategies according to question type. The system combines query understanding, biomedical document retrieval, reranking, knowledge graph augmentation, document clustering, and large language model-based answer generation. For yes/no questions, it focuses on precise evidence retrieval; for factoid and list questions, it emphasizes entity-oriented retrieval and clustering; and for summary questions, it performs broader evidence collection and synthesis. We evaluate the proposed framework on the BioASQ benchmark and demonstrate that adaptive retrieval strategies improve evidence relevance and answer quality across multiple question types. Our results suggest that aligning retrieval mechanisms with question-specific information needs provides an effective direction for enhancing retrieval-augmented biomedical QA systems.