The news is full of it: escalating tensions from illegal immigration; headless bodies hanging off bridges and bounties placed on lawmen on both sides of the border. New Austin, Ohio, is a town grappling with waves of undocumented workers who exert tremendous pressure on schools, police and city services. In the midst of the turmoil, three very different kinds of cops scramble to maintain control and impose order.

But the rape-murder of a Mexican-American woman triggers a brutal chain of events that threatens to leave no survivors. "El Gavilan" is a novel of shifting alliances and whiplash switchbacks. Families are divided and careers and lives threatened. Friendships and ideals are tested and budding love affairs challenged. With its topical themes, shades-of-gray characters and dark canvas, "El Gavilan" is a novel for our charged times.

This book constitutes the refereed proceedings of the 30th annual European Conference on Information Retrieval Research, ECIR 2008, held in Glasgow, UK, in March/April 2008.

The 33 revised full papers and 19 revised short papers presented together with the abstracts of 3 invited lectures and 32 poster papers were carefully reviewed and selected from 139 full article submissions. The papers are organized in topical sections on evaluation, Web IR, social media, cross-lingual information retrieval, theory, video, representation, wikipedia and e-books, as well as expert search.

This book constitutes the refereed proceedings of the 13th International Conference of the CLEF Association, CLEF 2022, held in Bologna, Italy in September 2022.The conference has a clear focus on experimental information retrieval with special attention to the challenges of multimodality, multilinguality, and interactive search ranging from unstructured to semi structures and structured data. The 7 full papers presented together with 3 short papers in this volume were carefully reviewed and selected from 14 submissions. This year, the contributions addressed the following challenges: authorship attribution, fake news detection and news tracking, noise-detection in automatically transferred relevance judgments, impact of online education on children's conversational search behavior, analysis of multi-modal social media content, knowledge graphs for sensitivity identification, a fusion of deep learning and logic rules for sentiment analysis, medical concept normalization and domain-specific information extraction. In addition to this, the volume presents 7 "best of the labs" papers which were reviewed as full paper submissions with the same review criteria. 14 lab overview papers were accepted and represent scientific challenges based on new datasets and real world problems in multimodal and multilingual information access.

This two-volume set LNCS 13185 and 13186 constitutes the refereed proceedings of the 44th European Conference on IR Research, ECIR 2022, held in April 2022, due to the COVID-19 pandemic. The 35 full papers presented together with 11 reproducibility papers, 13 CLEF lab descriptions papers, 12 doctoral consortium papers, 5 workshop abstracts, and 4 tutorials abstracts were carefully reviewed and selected from 395 submissions.

This two-volume set LNCS 13185 and 13186 constitutes the refereed proceedings of the 44th European Conference on IR Research, ECIR 2022, held in April 2022, due to the COVID-19 pandemic. The 35 full papers presented together with 11 reproducibility papers, 13 CLEF lab descriptions papers, 12 doctoral consortium papers, 5 workshop abstracts, and 4 tutorials abstracts were carefully reviewed and selected from 395 submissions. Chapter "Leveraging Customer Reviews for E-commerce Query Generation" of this book is available open access under a CC BY 4.0 license.

This book constitutes the refereed proceedings of the 7th International Conference of the CLEF Initiative, CLEF 2016, held in Toulouse, France, in September 2016. The 10 full papers and 8 short papers presented together with 5 best of the labs papers were carefully reviewed and selected from 36 submissions. In addition to these talks, this volume contains the results of 7 benchmarking labs reporting their year long activities in overview talks and lab sessions. The papers address all aspects of information access in any modality and language and cover a broad rangeof topics in the fields of multilingual and multimodal information access evaluation.

Every day, millions of users rely on search engines to satisfy the information needs required for performing many routine tasks. The effectiveness and efficiency of a search engine are two prime goals that form a natural trade-off. Meanwhile, search engines continue to rapidly evolve, with larger indexes, more complex retrieval strategies and growing query volumes. Hence, there is a need for efficient query processing infrastructures that make appropriate sacrifices in effectiveness in order to make gains in efficiency. This survey comprehensively reviews the foundations of search engines, from index layouts to basic query processing strategies, while also providing the latest trends in the literature in efficient query processing. It goes on to describe techniques in applying a cascading infrastructure within search systems, such as learned models obtained from learning-to-rank techniques. The survey also covers the selective application of query processing techniques to ensure that the required retrieval speed targets can be met. Finally, the authors bring the reader completely up-to-date by describing techniques for the efficient deployment of learned models in a multi-stage ranking system. Efficient Query Processing for Scalable Web Search will be a valuable reference for researchers and developers working on cutting edge of web system design where effective and efficient search is an integral part of the design.

Ranking in information retrieval has been traditionally approached as a pursuit of relevant information, under the assumption that the users' information needs are unambiguously conveyed by their submitted queries. Nevertheless, as an inherently limited representation of a more complex information need, every query can arguably be considered ambiguous to some extent. In order to tackle query ambiguity, search result diversification approaches have recently been proposed to produce rankings aimed to satisfy the multiple possible information needs underlying a query. This primer on the topic reviews the published literature on search result diversification. In particular, it discusses the motivations for diversifying the search results for an ambiguous query and provides a formal definition of the search result diversification problem. In addition, it describes the most successful approaches in the literature for producing and evaluating diversity in multiple search domains. Finally, it also discusses recent advances as well as open research directions in the field of search result diversification.