--- _id: '32509' abstract: - lang: eng text: " We consider fact-checking approaches that aim to predict the veracity of assertions in knowledge graphs. Five main categories of fact-checking approaches for knowledge graphs have been proposed in the recent literature, of\r\nwhich each is subject to partially overlapping limitations. In particular, current text-based approaches are limited by manual feature engineering. Path-based and rule-based approaches are limited by their exclusive use of knowledge graphs as background knowledge, and embedding-based approaches suffer from low accuracy scores on current fact-checking tasks. We propose a hybrid approach—dubbed HybridFC—that exploits the diversity of existing categories of fact-checking approaches within an ensemble learning setting to achieve a significantly better prediction performance. In particular, our approach outperforms the state of the art by 0.14 to 0.27 in terms of Area Under the Receiver Operating Characteristic curve on the FactBench dataset. Our code is open-source and can be found at https://github.com/dice-group/HybridFC." author: - first_name: Umair full_name: Qudus, Umair id: '83392' last_name: Qudus - first_name: Michael full_name: Röder, Michael last_name: Röder - first_name: Muhammad full_name: Saleem, Muhammad last_name: Saleem - first_name: Axel-Cyrille full_name: Ngonga Ngomo, Axel-Cyrille id: '65716' last_name: Ngonga Ngomo citation: ama: 'Qudus U, Röder M, Saleem M, Ngonga Ngomo A-C. HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs. In: Sattler U, Hogan A, Keet M, Presutti V, eds. The Semantic Web -- ISWC 2022. Springer International Publishing; :462--480. doi:10.1007/978-3-031-19433-7_27' apa: 'Qudus, U., Röder, M., Saleem, M., & Ngonga Ngomo, A.-C. (n.d.). HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs. In U. Sattler, A. Hogan, M. Keet, & V. Presutti (Eds.), The Semantic Web -- ISWC 2022 (pp. 462--480). Springer International Publishing. https://doi.org/10.1007/978-3-031-19433-7_27' bibtex: '@inproceedings{Qudus_Röder_Saleem_Ngonga Ngomo, place={Cham}, title={HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs}, DOI={10.1007/978-3-031-19433-7_27}, booktitle={The Semantic Web -- ISWC 2022}, publisher={Springer International Publishing}, author={Qudus, Umair and Röder, Michael and Saleem, Muhammad and Ngonga Ngomo, Axel-Cyrille}, editor={Sattler, Ulrike and Hogan, Aidan and Keet, Maria and Presutti, Valentina}, pages={462--480} }' chicago: 'Qudus, Umair, Michael Röder, Muhammad Saleem, and Axel-Cyrille Ngonga Ngomo. “HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs.” In The Semantic Web -- ISWC 2022, edited by Ulrike Sattler, Aidan Hogan, Maria Keet, and Valentina Presutti, 462--480. Cham: Springer International Publishing, n.d. https://doi.org/10.1007/978-3-031-19433-7_27.' ieee: 'U. Qudus, M. Röder, M. Saleem, and A.-C. Ngonga Ngomo, “HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs,” in The Semantic Web -- ISWC 2022, Hanghzou, China, pp. 462--480, doi: 10.1007/978-3-031-19433-7_27.' mla: 'Qudus, Umair, et al. “HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs.” The Semantic Web -- ISWC 2022, edited by Ulrike Sattler et al., Springer International Publishing, pp. 462--480, doi:10.1007/978-3-031-19433-7_27.' short: 'U. Qudus, M. Röder, M. Saleem, A.-C. Ngonga Ngomo, in: U. Sattler, A. Hogan, M. Keet, V. Presutti (Eds.), The Semantic Web -- ISWC 2022, Springer International Publishing, Cham, n.d., pp. 462--480.' conference: end_date: 2022-10-27 location: Hanghzou, China name: International Semantic Web Conference (ISWC) start_date: 2022-10-23 date_created: 2022-08-02T11:56:03Z date_updated: 2024-01-13T11:40:36Z ddc: - '000' department: - _id: '34' doi: 10.1007/978-3-031-19433-7_27 editor: - first_name: Ulrike full_name: Sattler, Ulrike last_name: Sattler - first_name: Aidan full_name: Hogan, Aidan last_name: Hogan - first_name: Maria full_name: Keet, Maria last_name: Keet - first_name: Valentina full_name: Presutti, Valentina last_name: Presutti file: - access_level: closed content_type: application/pdf creator: uqudus date_created: 2022-12-22T15:45:29Z date_updated: 2022-12-22T15:45:29Z file_id: '34853' file_name: hybrid_fact_check_iswc2022.pdf file_size: 296218 relation: main_file success: 1 file_date_updated: 2022-12-22T15:45:29Z has_accepted_license: '1' jel: - D keyword: - fact checking · ensemble learning · knowledge graph veracit language: - iso: eng page: 462--480 place: Cham project: - _id: '410' grant_number: '860801' name: 'KnowGraphs: KnowGraphs: Knowledge Graphs at Scale' publication: The Semantic Web -- ISWC 2022 publication_identifier: isbn: - 978-3-031-19433-7 publication_status: accepted publisher: Springer International Publishing status: public title: 'HybridFC: A Hybrid Fact-Checking Approach for Knowledge Graphs' type: conference user_id: '83392' year: '2022' ... --- _id: '25212' abstract: - lang: eng text: "Finding a good query plan is key to the optimization of query runtime. This holds in particular for cost-based federation\r\nengines, which make use of cardinality estimations to achieve this goal. A number of studies compare SPARQL federation engines across different performance metrics, including query runtime, result set completeness and correctness, number of sources selected and number of requests sent. Albeit informative, these metrics are generic and unable to quantify and evaluate the accuracy of the cardinality estimators of cost-based federation engines. To thoroughly evaluate cost-based federation engines, the effect of estimated cardinality errors on the overall query runtime performance must be measured. In this paper, we address this challenge by presenting novel evaluation metrics targeted at a fine-grained benchmarking of cost-based federated SPARQL query engines. We evaluate five cost-based federated SPARQL query engines using existing as well as novel evaluation metrics by using LargeRDFBench queries. Our results provide a detailed analysis of the experimental outcomes that reveal novel insights, useful for the development of future cost-based federated SPARQL query processing engines." article_type: original author: - first_name: Umair full_name: Qudus, Umair id: '83392' last_name: Qudus - first_name: Muhammad full_name: Saleem, Muhammad last_name: Saleem - first_name: Axel-Cyrille full_name: Ngonga Ngomo, Axel-Cyrille id: '65716' last_name: Ngonga Ngomo - first_name: Young-Koo full_name: Lee, Young-Koo last_name: Lee citation: ama: Qudus U, Saleem M, Ngonga Ngomo A-C, Lee Y-K. An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines. Semantic Web. 12(6):843-868. doi:10.3233/SW-200420 apa: Qudus, U., Saleem, M., Ngonga Ngomo, A.-C., & Lee, Y.-K. (n.d.). An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines. Semantic Web, 12(6), 843–868. https://doi.org/10.3233/SW-200420 bibtex: '@article{Qudus_Saleem_Ngonga Ngomo_Lee, title={An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines}, volume={12}, DOI={10.3233/SW-200420}, number={6}, journal={Semantic Web}, publisher={ISO Press}, author={Qudus, Umair and Saleem, Muhammad and Ngonga Ngomo, Axel-Cyrille and Lee, Young-Koo}, pages={843–868} }' chicago: 'Qudus, Umair, Muhammad Saleem, Axel-Cyrille Ngonga Ngomo, and Young-Koo Lee. “An Empirical Evaluation of Cost-Based Federated SPARQL Query Processing Engines.” Semantic Web 12, no. 6 (n.d.): 843–68. https://doi.org/10.3233/SW-200420.' ieee: 'U. Qudus, M. Saleem, A.-C. Ngonga Ngomo, and Y.-K. Lee, “An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines,” Semantic Web, vol. 12, no. 6, pp. 843–868, doi: 10.3233/SW-200420.' mla: Qudus, Umair, et al. “An Empirical Evaluation of Cost-Based Federated SPARQL Query Processing Engines.” Semantic Web, vol. 12, no. 6, ISO Press, pp. 843–68, doi:10.3233/SW-200420. short: U. Qudus, M. Saleem, A.-C. Ngonga Ngomo, Y.-K. Lee, Semantic Web 12 (n.d.) 843–868. date_created: 2021-10-01T06:52:52Z date_updated: 2024-01-13T11:40:25Z ddc: - '000' department: - _id: '574' doi: 10.3233/SW-200420 file: - access_level: closed content_type: application/pdf creator: uqudus date_created: 2024-01-13T11:35:53Z date_updated: 2024-01-13T11:35:53Z file_id: '50483' file_name: swj2604.pdf file_size: 978478 relation: main_file success: 1 file_date_updated: 2024-01-13T11:35:53Z has_accepted_license: '1' intvolume: ' 12' issue: '6' keyword: - SPARQL - benchmarking - cost-based - cost-free - federated - querying language: - iso: eng page: 843-868 project: - _id: '410' grant_number: '860801' name: 'KnowGraphs: KnowGraphs: Knowledge Graphs at Scale' publication: Semantic Web publication_identifier: issn: - 2210-4968 publication_status: accepted publisher: ISO Press status: public title: An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines type: journal_article user_id: '83392' volume: 12 year: '2021' ...