This book constitutes the refereed proceedings of the Second International Conference on the Theory of Information Retrieval, ICTIR 2009, held in Cambridge, UK, in September 2009. The 18 revised full papers, 14 short papers, and 11 posters presented together with one invited talk were carefully reviewed and selected from 82 submissions. The papers are categorized into four main themes: novel IR models, evaluation, efficiency, and new perspectives in IR. Twenty-one papers fall into the general theme of novel IR models, ranging from various retrieval models, query and term selection models, Web IR models, developments in novelty and diversity, to the modeling of user aspects. There are four papers on new evaluation methodologies, e.g., modeling score distributions, evaluation over sessions, and an axiomatic framework for XML retrieval evaluation. Three papers focus on the issue of efficiency and offer solutions to improve the tractability of PageRank, data cleansing practices for training classifiers, and approximate search for distributed IR. Finally, four papers look into new perspectives of IR and shed light on some new emerging areas of interest, such as the application and adoption of quantum theory in IR.

This two-volume set LNCS 12656 and 12657 constitutes the refereed proceedings of the 43rd European Conference on IR Research, ECIR 2021, held virtually in March/April 2021, due to the COVID-19 pandemic. The 50 full papers presented together with 11 reproducibility papers, 39 short papers, 15 demonstration papers, 12 CLEF lab descriptions papers, 5 doctoral consortium papers, 5 workshop abstracts, and 8 tutorials abstracts were carefully reviewed and selected from 436 submissions. The accepted contributions cover the state of the art in IR: deep learning-based information retrieval techniques, use of entities and knowledge graphs, recommender systems, retrieval methods, information extraction, question answering, topic and prediction models, multimedia retrieval, and much more.

This book constitutes the refereed proceedings of the Third International Conference on the Theory of Information Retrieval, ICTIR 2011, held in Bertinoro, Italy, in September 2011. The 25 revised full papers and 13 short papers presented together with the abstracts of two invited talks were carefully reviewed and selected from 65 submissions. The papers cover topics ranging from query expansion, co-occurence analysis, user and interactive modelling, system performance prediction and comparison, and probabilistic approaches for ranking and modelling IR to topics related to interdisciplinary approaches or applications. They are organized into the following topical sections: predicting query performance; latent semantic analysis and word co-occurrence analysis; query expansion and re-ranking; comparison of information retrieval systems and approximate search; probability ranking principle and alternatives; interdisciplinary approaches; user and relevance; result diversification and query disambiguation; and logical operators and descriptive approaches.

This book constitutes the proceedings of the 35th European Conference on IR Research, ECIR 2013, held in Moscow, Russia, in March 2013. The 55 full papers, 38 poster papers and 10 demonstrations presented in this volume were carefully reviewed and selected from 287 submissions. The papers are organized in the following topical sections: user aspects; multimedia and cross-media IR; data mining; IR theory and formal models; IR system architectures; classification; Web; event detection; temporal IR, and microblog search. Also included are 4 tutorial and 2 workshop presentations.

Class-tested and coherent, this textbook teaches classical and web information retrieval, including web search and the related areas of text classification and text clustering from basic concepts. It gives an up-to-date treatment of all aspects of the design and implementation of systems for gathering, indexing, and searching documents; methods for evaluating systems; and an introduction to the use of machine learning methods on text collections. All the important ideas are explained using examples and figures, making it perfect for introductory courses in information retrieval for advanced undergraduates and graduate students in computer science. Based on feedback from extensive classroom experience, the book has been carefully structured in order to make teaching more natural and effective. Slides and additional exercises (with solutions for lecturers) are also available through the book's supporting website to help course instructors prepare their lectures.

The Center for Intelligent Information Retrieval (CIIR) was formed in the Computer Science Department ofthe University ofMassachusetts, Amherst in 1992. The core support for the Center came from a National Science Foun- tion State/Industry/University Cooperative Research Center(S/IUCRC) grant, although there had been a sizeable information retrieval (IR) research group for over 10 years prior to that grant. Thebasic goal ofthese Centers is to combine basic research, applied research, and technology transfer. The CIIR has been successful in each of these areas, in that it has produced over 270 research papers, has been involved in many successful government and industry collaborations, and has had a significant role in high-visibility Internet sites and start-ups. As a result of these efforts, the CIIR has become known internationally as one of the leading research groups in the area of information retrieval. The CIIR focuses on research that results in more effective and efficient access and discovery in large, heterogeneous, distributed, text and multimedia databases. The scope of the work that is done in the CIIR is broad and goes significantly beyond “traditional” areas of information retrieval such as retrieval models, cross-lingual search, and automatic query expansion. The research includes both low-level systems issues such as the design of protocols and architectures for distributed search, as well as more human-centered topics such as user interface design, visualization and data mining with text, and multimedia retrieval.

These proceedings contain the papers presented at ECIR 2010, the 32nd Eu- pean Conference on Information Retrieval. The conference was organizedby the Knowledge Media Institute (KMi), the Open University, in co-operation with Dublin City University and the University of Essex, and was supported by the Information Retrieval Specialist Group of the British Computer Society (BCS- IRSG) and the Special Interest Group on Information Retrieval (ACM SIGIR). It was held during March 28-31, 2010 in Milton Keynes, UK. ECIR 2010 received a total of 202 full-paper submissions from Continental Europe (40%), UK (14%), North and South America (15%), Asia and Australia (28%), Middle East and Africa (3%). All submitted papers were reviewed by at leastthreemembersoftheinternationalProgramCommittee.Outofthe202- pers 44 were selected asfull researchpapers. ECIR has alwaysbeen a conference with a strong student focus. To allow as much interaction between delegates as possible and to keep in the spirit of the conference we decided to run ECIR 2010 as a single-track event. As a result we decided to have two presentation formats for full papers. Some of them were presented orally, the others in poster format. The presentation format does not represent any di?erence in quality. Instead, the presentation format was decided after the full papers had been accepted at the Program Committee meeting held at the University of Essex. The views of the reviewers were then taken into consideration to select the most appropriate presentation format for each paper.

This book constitutes the refereed proceedings of the 15th Information Retrieval Technology Conference, AIRS 2019, held in Hong Kong, China, in November 2019.The 14 full papers presented together with 3 short papers were carefully reviewed and selected from 27 submissions. The scope of the conference covers applications, systems, technologies and theory aspects of information retrieval in text, audio, image, video and multimedia data.

Information visualization offers a way to reveal hidden patterns in a visual presentation and allows users to seek information from a visual perspective. Readers of this book will gain an in-depth understanding of the current state of information retrieval visualization. They will be introduced to existing problems along with technical and theoretical findings. The book also provides practical details for the implementation of an information retrieval visualization system.

The European Conference on Information Retrieval Research, now in its 25th “Silver Jubilee” edition, was initiallyestablished bythe Information Retrieval Specialist Group of the British Computer Society(BCS-IRSG) under the name “Annual Colloquium on Information Retrieval Research,” and was always held in the United Kingdom until 1997. Since 1998 the location of the colloquium has alternated between the United Kingdom and the rest of Europe, in order to re?ect the growing European orientation of the event. For the same reason, in 2001 the event was renamed “European Annual Colloquium on Information Retrieval Research.” Since 2002, the proceedings of the Colloquium have been published bySpringer-Verlag in their Lecture Notes in Computer Science series. In 2003 BCS-IRSG decided to rename the event “European Conference on Information Retrieval Research,” in order to re?ect what the event had slowly turned into, i.e., a full-blown conference with a European program committee, strong peer reviewing, and a (mostly) European audience. However, ECIR still retains the strong student focus that has characterized the Colloquia since their inception: student fees are kept particularlylow, a s- dent travel grant program is available in order to encourage students to attend the conference (and encourage student authors to present their papers pers- ally), and a Best Student Paper Award is assigned (conversely, ECIR has no best paper award).