This volume contains the papers presented at the Eleventh Flexible Query Answering Systems 2015 (FQAS-2015) held on October 26-28, 2015 in Cracow, Poland. The international conferences on Flexible Query Answering Systems (FQAS) are a series of premier conferences focusing on the key issue in the information society of providing easy, flexible, and intuitive access to information and knowledge to everybody, even people with a very limited computer literacy. In targeting this issue, the Conference draws on several research areas, such as information retrieval, database management, information filtering, knowledge representation, soft computing, management of multimedia information, and human-computer interaction. The Conference provides a unique opportunity for researchers, developers and practitioners to explore new ideas and approaches in a multidisciplinary forum.

Flexible Query Answering Systems is an edited collection of contributed chapters. It focuses on developing computer systems capable of transforming a query into an answer with useful information. The emphasis is on problems associated with high-level intelligent answering systems. The coverage is multidisciplinary with chapters by authors from information science, logic, fuzzy systems, databases, artificial intelligence and knowledge representation. Each contribution represents a theory involving flexibility in query-answering, and each addresses specific answering problems. Coverage includes topics such as fuzzy sets in flexible querying, non-standard database interactions, metareasoning and agents, and many others. Contributions for this volume were written by leading researchers from their respective subject areas, including Patrick Bosc, Bernadette Bouchon-Meunier, Amihai Motro, Henri Prade and Ron Yager, among others. Flexible Query Answering Systems is a timely contribution for researchers working on high-level query mechanism systems.

This book constitutes the refereed proceedings of the 13th International Conference on Flexible Query Answering Systems, FQAS 2019, held in Amantea, Italy, in July 2019. The 27 full papers and 10 short papers presented were carefully reviewed and selected from 43 submissions. The papers present emerging research trends with a special focus on flexible querying and analytics for smart cities and smart societies in the age of big data. They are organized in the following topical sections: flexible database management and querying; ontologies and knowledge bases; social networks and social media; argumentation-based query answering; data mining and knowledge discovery; advanced flexible query answering methodologies and techniques; flexible query answering methods and techniques; flexible intelligent information-oriented and network-oriented approaches; big data veracity and soft computing; flexibility in tools; and systems and miscellanea.

This book constitutes the refereed proceedings of the 14th International Conference on Flexible Query Answering Systems, FQAS 2021, held virtually and in Bratislava, Slovakia, in September 2021. The 16 full papers and 1 perspective papers presented were carefully reviewed and selected from 17 submissions. They are organized in the following topical sections: model-based flexible query answering approaches and data-driven approaches.

This book constitutes the refereed proceedings of the 12th International Conference on Flexible Query Answering Systems, FQAS 2017, held in London, UK, in June 2017. The 21 full papers presented in this book together with 4 short papers were carefully reviewed and selected from 43 submissions. The papers cover the following topics: foundations of flexible querying; recommendation and ranking; technologies for flexible representations and querying; knowledge discovery and information/data retrieval; intuitionistic sets; and generalized net model.

This book constitutes the refereed proceedings of the 7th International Conference on Flexible Query Answering Systems, FQAS 2006, held in Milan, Italy in June 2006. The book presents 60 revised full papers, organized in topical sections on flexibility in database management and querying, vagueness and uncertainty in XML querying and retrieval, information retrieval and filtering, multimedia information access, user modeling and personalization, knowledge and data extraction, and more.