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 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.

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 volume constitutes the proceedings of the Fourth International Conference on Flexible Query Answering Systems, FQAS'2000, held in Warsaw, Poland on October 25 - 28, 2000. The FQAS conference has been the premier conference focusing on one of key issues that the information society faces, namely that of providing easy, flexible, intuitive access to information for everybody. In targeting this issue, the conference draws on several research areas, such as databases, querying, information retrieval, knowledge representation, soft computing, cyberspace, multimedia systems, human-computer interaction, etc. FQAS'2000 has been preceded by the extremely successful FQAS'94, FQAS'96 and FQAS'98 conferences all held in Roskilde, Denmark. The present conference provides a unique opportunity for researchers, developers and practitioners to explore new ideas and approaches in a multidisciplinary forum. As a metaphor for flexible query answering we may consider a human intermediary who has expertise in the topic of the query, and is experienced in identifying the user's information needs and answering the needs from the available information resources. The use of knowledge on relevant contexts, available information resources, etc. , enables the expert to respond rather precisely to the needs, though the query, per se, may be imprecise, incomplete, etc. Thus, a key issue for flexible query answering system is to obtain, maintain, represent, and utilize such knowledge. This comprises domain knowledge and metaknowledge, its representation and organization in ontologies, terminologies, etc.

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 15th International Conference on Flexible Query Answering Systems, FQAS 2023, held in September 2023 in Palma de Mallorca, Spain. The 24 full papers presented were carefully reviewed and selected from numerous submissions. They are organized in the following topical sections: Flexible Queries over Semantic Systems; Advanced Methods and Applications in Natural Language; Processing (NLP); New Advances in Disinformation Detection; Data and Text Mining; Applying AI to Social Science and Social Science to AI; Artificial Intelligence Law and Regulation.

Integrity constraints are semantic conditions that a database should satisfy in order to be an appropriate model of external reality. In practice, and for many reasons, a database may not satisfy those integrity constraints, and for that reason it is said to be inconsistent. However, and most likely, a large portion of the database is still semantically correct, in a sense that has to be made precise. After having provided a formal characterization of consistent data in an inconsistent database, the natural problem emerges of extracting that semantically correct data, as query answers. The consistent data in an inconsistent database is usually characterized as the data that persists across all the database instances that are consistent and minimally differ from the inconsistent instance. Those are the so-called repairs of the database. In particular, the consistent answers to a query posed to the inconsistent database are those answers that can be simultaneously obtained from all the database repairs. As expected, the notion of repair requires an adequate notion of distance that allows for the comparison of databases with respect to how much they differ from the inconsistent instance. On this basis, the minimality condition on repairs can be properly formulated. In this monograph we present and discuss these fundamental concepts, different repair semantics, algorithms for computing consistent answers to queries, and also complexity-theoretic results related to the computation of repairs and doing consistent query answering. Table of Contents: Introduction / The Notions of Repair and Consistent Answer / Tractable CQA and Query Rewriting / Logically Specifying Repairs / Decision Problems in CQA: Complexity and Algorithms / Repairs and Data Cleaning