PMID- 34604514 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20211005 IS - 2376-5992 (Electronic) IS - 2376-5992 (Linking) VI - 7 DP - 2021 TI - A knowledge graph based question answering method for medical domain. PG - e667 LID - 10.7717/peerj-cs.667 [doi] LID - e667 AB - Question answering (QA) is a hot field of research in Natural Language Processing. A big challenge in this field is to answer questions from knowledge-dependable domain. Since traditional QA hardly satisfies some knowledge-dependable situations, such as disease diagnosis, drug recommendation, etc. In recent years, researches focus on knowledge-based question answering (KBQA). However, there still exist some problems in KBQA, traditional KBQA is limited by a range of historical cases and takes too much human labor. To address the problems, in this paper, we propose an approach of knowledge graph based question answering (KGQA) method for medical domain, which firstly constructs a medical knowledge graph by extracting named entities and relations between the entities from medical documents. Then, in order to understand a question, it extracts the key information in the question according to the named entities, and meanwhile, it recognizes the questions' intentions by adopting information gain. The next an inference method based on weighted path ranking on the knowledge graph is proposed to score the related entities according to the key information and intention of a given question. Finally, it extracts the inferred candidate entities to construct answers. Our approach can understand questions, connect the questions to the knowledge graph and inference the answers on the knowledge graph. Theoretical analysis and real-life experimental results show the efficiency of our approach. CI - (c) 2021 Huang et al. FAU - Huang, Xiaofeng AU - Huang X AD - School of Computer Science, Hubei University of Technology, Wuhan, Hubei, China. FAU - Zhang, Jixin AU - Zhang J AD - School of Computer Science, Hubei University of Technology, Wuhan, Hubei, China. FAU - Xu, Zisang AU - Xu Z AD - Computer and Communication Engineer Institute, Changsha University of Science and Technology, Changsha, Hunan, China. FAU - Ou, Lu AU - Ou L AD - College of Computer Science and Electronic Engineering, Hunan University, Changsha, Hunan, China. FAU - Tong, Jianbin AU - Tong J AD - Hunan Province Key Laboratory of Brain Homeostasis, Third Xiangya Hospital, Central South University, Changsha, Hunan, China. LA - eng PT - Journal Article DEP - 20210901 PL - United States TA - PeerJ Comput Sci JT - PeerJ. Computer science JID - 101660598 PMC - PMC8444078 OTO - NOTNLM OT - Knowledge graph OT - Medical domain OT - Question answering OT - Weighted path ranking COIS- The authors declare that they have no competing interests. EDAT- 2021/10/05 06:00 MHDA- 2021/10/05 06:01 PMCR- 2021/09/01 CRDT- 2021/10/04 06:11 PHST- 2020/11/27 00:00 [received] PHST- 2021/07/19 00:00 [accepted] PHST- 2021/10/04 06:11 [entrez] PHST- 2021/10/05 06:00 [pubmed] PHST- 2021/10/05 06:01 [medline] PHST- 2021/09/01 00:00 [pmc-release] AID - cs-667 [pii] AID - 10.7717/peerj-cs.667 [doi] PST - epublish SO - PeerJ Comput Sci. 2021 Sep 1;7:e667. doi: 10.7717/peerj-cs.667. eCollection 2021.