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Local context is not enough! Towards Query Semantic and Knowledge Guided Multi-Span Medical Question Answering
ISSN
09226389
Date Issued
2023-09-28
Author(s)
Tiwari, Abhisek
Bhansali, Aman
Saha, Sriparna
Bhattacharyya, Pushpak
Verma, Preeti
Dhar, Minakshi
DOI
10.3233/FAIA230536
Abstract
Medical Question Answering (MedQA) is one of the most popular and significant tasks in developing healthcare assistants. When humans extract an answer to a question from a document, they first (a) understand the question itself in detail and (b) utilize relevant knowledge/experiences to determine the answer segments. In multi-span question answering, it becomes increasingly important to comprehend the query accurately and possess relevant knowledge, as the interrelationship among different answer segments is essential for achieving completeness. Motivated by this, we first propose a transformer-based query semantic and knowledge (QueSemKnow) guided multi-span question-answering model. The proposed QueSemKnow works in a two-phased manner; in the first stage, a multi-task model is proposed to extract query semantics: (i) intent identification and (ii) question type prediction. In the second stage, QueSemKnow selects a relevant subset of the knowledge graph as the underlying context/document and extracts answers depending on the semantic information extracted from the first stage and context. We build a multi-task query semantic extraction model for query intent and query type identification to investigate the co-relation among these tasks. Furthermore, we created a semantically aware medical question-answering corpus named QueSeMSpan MedQA wherein each question is annotated with its corresponding semantic information. The proposed model outperforms several baselines and existing state-of-the-art models by a large margin on multiple datasets, which firmly demonstrates the effectiveness of the human-inspired multi-span question-answering methodology.