Proceedings of the 13th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management Acronym: KDIR 2021/IC3K Event held on: October 25-27, 2021 Editors: Rita Cucchiara 1 , Ana Fred 2 and Joaquim Filipe 3 Affiliations: 1 University of Modena and Reggio Emilia, Italy , 2 Instituto de Telecomunicações and University of Lisbon, Portugal , 3 Polytechnic Institute of Setubal / INSTICC, Portugal Vol. 1 - 978-989-758-533-3 Vol. 2 - 978-989-758-533-3 Vol. 3 - 978-989-758-533-3