TY - JOUR AB - Purpose Semantic Web is an extension of the World Wide Web by tagging content with “meaning”. In general, question answering systems based on semantic Web face a number of difficult issues. This paper aims to design an experimental environment with custom rules and scalable data sets and evaluate the performance of a proposed optimized backward chaining ontology reasoning system. This study also compares the experimental results with other ontology reasoning systems to show the performance and scalability of this ontology reasoning system.Design/methodology/approach The authors proposed a semantic question answering system. This system has been built using ontological knowledge base including optimized backward chaining ontology reasoning system and custom rules. With custom rules, the proposed semantic question answering system will be able to answer questions that contain qualitative descriptors such as “groundbreaking” resesarch and “tenurable at university x”. Scalability has been one of the difficult issues faced by an optimized backward chaining ontology reasoning system and semantic question answering system. To evaluate the proposed ontology reasoning system, first, the authors design a number of innovative custom rule sets and corresponding query sets. The innovative custom rule sets and query sets will contribute to the future research on evaluating ontology reasoning systems as well. Then they design an experimental environment including ontologies and scalable data sets and metrics. Furthermore, they evaluate the performance of the proposed optimized backward chaining reasoning system on supporting custom rules. The evaluation results have been compared with other ontology reasoning systems as well.Findings The proposed innovative custom rules and query sets can be effectively employed for evaluating ontology reasoning systems. The evaluation results show that the scalability of the proposed backward chaining ontology reasoning system is better than in-memory reasoning systems. The proposed semantic question answering system can be integrated in sematic Web applications to solve scalability issues. For light weight applications, such as mobile applications, in-memory reasoning systems will be a better choice.Originality/value This paper fulfils an identified need for a study on evaluating an ontology reasoning system on supporting custom rules with and without external storage. VL - 46 IS - 1 SN - 2398-6247 DO - 10.1108/IDD-10-2017-0070 UR - https://doi.org/10.1108/IDD-10-2017-0070 AU - Shi Hui AU - Chong Dazhi AU - Yan Gongjun PY - 2018 Y1 - 2018/01/01 TI - Evaluating an optimized backward chaining ontology reasoning system with innovative custom rules T2 - Information Discovery and Delivery PB - Emerald Publishing Limited SP - 45 EP - 56 Y2 - 2024/04/19 ER -