Deep Learning I -- Seed-guided Deep Document Clustering -- Improving Knowledge Graph Embedding using Locally and Globally Attentive Relation Paths -- ReadNet: A Hierarchical Transformer Framework for Web Article Readability Analysis -- Variational Recurrent Sequence-to-Sequence Retrieval for Stepwise Illustration -- A Hierarchical Model for Data-to-Text Generation -- Entities -- Context-guided Learning to Rank Entities -- Graph-Embedding Empowered Entity Retrieval -- Learning Advanced Similarities and Training Features for Toponym Interlinking -- Patch-based Identification of Lexical Semantic Relations -- Joint Word and Entity Embeddings for Entity Retrieval from a Knowledge Graph -- Evaluation -- Evaluating the Effectiveness of the Standard Insights Extraction Pipeline for Bantu Languages -- Recommendation -- Axiomatic Analysis of Contact Recommendation Methods in Social Networks: an IR perspective -- Recommending Music Curators: A Neural Style-Aware Approach -- Joint Geographical and Temporal Modeling based on Matrix Factorization for Point-of-Interest Recommendation -- Semantic Modelling of Citation Contexts for Context-aware Citation Recommendation -- TransRev: Modeling Reviews as Translations from Users to Items -- Information Extraction -- Domain-independent Extraction of Scientific Concepts from Research Articles -- Leveraging Schema Labels to Enhance Dataset Search -- Moving from formal towards coherent concept analysis: why, when and how -- Beyond Modelling: Understanding Mental Disorders in Online Social Media -- Deep Learning II -- Learning based Methods for Code Runtime Complexity Prediction -- Inductive Document Network Embedding with Topic-Word Attention -- Multi-components system for automatic Arabic diacritization -- A Mixed Semantic Features Model for Chinese NER with Characters and Words -- VGCN-BERT: Augmenting BERT with Graph Embedding for Text Classification -- Retrieval -- A Computational Approach for Objectively Derived Systematic Review Search Strategies -- You Can Teach an Old Dog New Tricks: Rank Fusion applied to Coordination Level Matching for Ranking in Systematic Reviews -- Counterfactual Online Learning to Rank -- A Framework for Argument Retrieval: Ranking Argument Clusters by Frequency and Specificity -- Relevance Ranking based on Query-Aware Context Analysis -- Multimedia -- Multimodal Entity Linking for Tweets -- MEMIS: Multimodal Emergency Management Information System -- Interactive Learning for Multimedia at Large -- Visual Re-ranking via Adaptive Collaborative Hypergraph Learning for Image Retrieval -- Motion Words: A Text-like Representation of 3D Skeleton Sequences -- Deep Learning III -- Reinforced Rewards Framework for Text Style Transfer -- Recognizing Semantic Relations: Attention-Based Transformers vs. Recurrent Models -- Early detection of rumours on Twitter via stance transfer learning -- Learning to Rank Images with Cross-Modal Graph Convolutions -- Diagnosing BERT with RetrievalHeuristics -- Queries -- Generation of Synthetic Query Auto Completion Logs -- What Can Task Teach Us About Query Reformulations? -- A Regularised Intent Model for Discovering Multiple Intents in E-Commerce Tail Queries -- Utilising Information Foraging Theory for User Interaction with Image Query Auto-Completion -- Using Image Captions and Multitask Learning for Recommending Query Reformulations -- IR - general -- Curriculum Learning Strategies for IR: An Empirical Study on Conversation Response Ranking -- Accelerating Substructure Similarity Search for Formula Retrieval -- Quantum-like Structure in Multidimensional Relevance Judgements -- Question Answering, Prediction, and Bias -- Temporal Latent Space Modeling for Community Prediction -- KvGR: A Graph-Based Interface for Explorative Sequential Question Answering on Heterogeneous Information Sources -- Answering Event-Related Questions over Long-term News Article Archives -- bias goggles - Graph-based Computation of the Bias of Web Domains through the Eyes of Users -- Deep Learning IV -- Biconditional Generative Adversarial Networks for Multiview Learning with Missing Views -- Semantic Path-Based Learning for Review Volume Prediction -- An Attention Model of Customer Expectation to Improve Review Helpfulness Prediction.

This two-volume set LNCS 12035 and 12036 constitutes the refereed proceedings of the 42nd European Conference on IR Research, ECIR 2020, held in Lisbon, Portugal, in April 2020.* The 55 full papers presented together with 8 reproducibility papers, 46 short papers, 10 demonstration papers, 12 invited CLEF papers, 7 doctoral consortium papers, 4 workshop papers, and 3 tutorials were carefully reviewed and selected from 457 submissions. They were organized in topical sections named: Part I: deep learning I; entities; evaluation; recommendation; information extraction; deep learning II; retrieval; multimedia; deep learning III; queries; IR - general; question answering, prediction, and bias; and deep learning IV. Part II: reproducibility papers; short papers; demonstration papers; CLEF organizers lab track; doctoral consortium papers; workshops; and tutorials. *Due to the COVID-19 pandemic, this conference was held virtually.