This book constitutes the refereed proceedings of the 38th European Conference on IR Research, ECIR 2016, held in Padua, Italy, in March 2016. The 42 full papers and 28 poster papers presented together with 3 keynote talks and 6 demonstration papers, were carefully reviewed and selected from 284 submissions. The volume contains the outcome of 4 workshops as well as 4 tutorial papers in addition. Being the premier European forum for the presentation of new research results in the field of Information Retrieval, ECIR features a wide range of topics such as: social context and news, machine learning, question answering, ranking, evaluation methodology, probalistic modeling, evaluation issues, multimedia and collaborative filtering, and many more.

This book constitutes the refereed proceedings of the 39th European Conference on IR Research, ECIR 2017, held in Aberdeen, UK, in April 2017. The 36 full papers and 47 poster papers presented together with 5 Abstracts, were carefully reviewed and selected from 248 submissions. Being the premier European forum for the presentation of new research results in the field of Information Retrieval, ECIR features a wide range of topics such as: IR Theory and Practice; Deep Learning and IR; Web and Social Media IR; User Aspects; IR System Architectures; Content Representation and Processing; Evaluation; Multimedia and Cross-Media IR; Applications.

This two-volume set LNCS 11437 and 11438 constitutes the refereed proceedings of the 41st European Conference on IR Research, ECIR 2019, held in Cologne, Germany, in April 2019. The 48 full papers presented together with 2 keynote papers, 44 short papers, 8 demonstration papers, 8 invited CLEF papers, 11 doctoral consortium papers, 4 workshop papers, and 4 tutorials were carefully reviewed and selected from 365 submissions. They were organized in topical sections named: Modeling Relations; Classification and Search; Recommender Systems; Graphs; Query Analytics; Representation; Reproducibility (Systems); Reproducibility (Application); Neural IR; Cross Lingual IR; QA and Conversational Search; Topic Modeling; Metrics; Image IR; Short Papers; Demonstration Papers; CLEF Organizers Lab Track; Doctoral Consortium Papers; Workshops; and Tutorials.

This two-volume set LNCS 11437 and 11438 constitutes the refereed proceedings of the 41st European Conference on IR Research, ECIR 2019, held in Cologne, Germany, in April 2019. The 48 full papers presented together with 2 keynote papers, 44 short papers, 8 demonstration papers, 8 invited CLEF papers, 11 doctoral consortium papers, 4 workshop papers, and 4 tutorials were carefully reviewed and selected from 365 submissions. They were organized in topical sections named: Modeling Relations; Classification and Search; Recommender Systems; Graphs; Query Analytics; Representation; Reproducibility (Systems); Reproducibility (Application); Neural IR; Cross Lingual IR; QA and Conversational Search; Topic Modeling; Metrics; Image IR; Short Papers; Demonstration Papers; CLEF Organizers Lab Track; Doctoral Consortium Papers; Workshops; and Tutorials.