This volume LNCS 14163 constitutes the refereed proceedings of 14th International Conference of the CLEF Association, CLEF 2023, in Thessaloniki, Greece, during September 18–21, 2023.   The 10 full papers and one short paper included in this book were carefully reviewed and selected from 35 submissions. The conference focuses on 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. 13 lab overview papers were accepted and represent scientific challenges based on new datasets and real world problems in multimodal and multilingual information access.

This book constitutes the refereed proceedings of the 11th International Conference of the CLEF Association, CLEF 2020, held in Thessaloniki, Greece, in September 2020.*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 5 full papers and 2 short papers presented in this volume were carefully reviewed and selected from 9 submissions. This year, the contributions addressed the following challenges: a large-scale evaluation of translation effects in academic search, advancement of assessor-driven aggregation methods for efficient relevance assessments, and development of a new test dataset. 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. The 12 lab overview papers were accepted out of 15 submissions and represent scientific challenges based on new data sets and real world problems in multimodal and multilingual information access. * The conference was held virtually due to the COVID-19 pandemic.