This book constitutes the proceedings of the 37th European Conference on IR Research, ECIR 2015, held in Vienna, Austria, in March/April 2015.The 44 full papers, 41 poster papers and 7 demonstrations presented together with 3 keynotes in this volume were carefully reviewed and selected from 305 submissions. The focus of the papers were on following topics:  aggregated search and diversity, classification, cross-lingual and discourse, efficiency, evaluation, event mining and summarisation, information extraction, recommender systems, semantic and graph-based models, sentiment and opinion, social media, specific search tasks, temporal models and features, topic and document models, user behavior,  and reproducible IR.

Keynotes.- Still Haven't Found What I'm Looking For: Suggestions for Search Research.- Mining and Modeling Online Health Search.- What to do if you know everything? Studying human behavior in a virtual world.- Aggregated Search and Diversity.- Towards Query Level Resource Weighting For Diversified Query Expansion.- Exploring Composite Retrieval from the Users' Perspective.- Improving Aggregated Search Coherence.- On-topic Cover Stories from News Archives.- Classification.- Multi-Emotion Detection in User-Generated Reviews.- Classification of historical notary acts with noisy labels.- ConceptFusion: A Flexible Scene Classification Framework.- An Audio-Visual Approach to Music Genre Classiffcation through Affective Color Features.- Cross-Lingual and Discourse.- Multi-Modal Correlated Centroid Space for Multi-Lingual Cross-Modal Retrieval.- A Discourse Search Engine based on Rhetorical Structure Theory.- Knowledge-based Representation for Transductive Multilingual Document Classiffcation.- Distributional Correspondence Indexing for Cross-Language Text Categorization.- Effciency Adaptive Caching of Fresh Web Search Results.- Approximating Weighted Hamming Distance by Probabilistic Selection for Multiple Hash Table.- Graph Regularised Hashing.- Approximate Nearest-Neighbour Search with Inverted Signature Slice Lists.- Evaluation.- A Discriminative Approach to Predicting Assessor Accuracy.- WHOSE A Tool for Whole-Session Analysis in IIR.- Looking for Books in Social Media: An Analysis of Complex Search Requests.- How do Gain and Discount Functions Affect the Correlation between DCG and User Satisfaction?.- Different Rankers on Different Subcollections.- Retrievability Bias: A Comparison of Inequality Measures.- Judging Relevance Using Magnitude Estimation.- Event Mining and Summarisation.- Retrieving Time from Scanned Books.- A Noise-Filtering Approach for Spatio-Temporal Event Detection in Social Media.- Timeline Summarization from Relevant Headlines.- Information Extraction.- A Self-Training CRF Method for Recognizing Product Model Mentions in Web Forums.- Information Extraction Grammars.- Target-based Topic Model for Problem Phrase Extraction.- On Identifying Phrases Using Collection Statistics.- MIST: Top-k Approximate Sub-String Mining using Triplet Statistical Significance.- Recommender Systems.- Active Learning applied to Rating Elicitation for Incentive Purposes.- Entity-Centric Stream Filtering and ranking: Filtering and Unfilterable Documents.- Generating Music Playlists with Hierarchical Clustering and Q-Learning.- Time-sensitive Collaborative Filtering through Adaptive Matrix Completion.- Toward the New Item Problem: Context-enhanced Event Recommendation in Event-based Social Networks.- On the Infence of User Characteristics on Music Recommendation Algorithms.- A Study of Smoothing Methods for Relevance-Based Language Modelling of Recommender Systems.- The Power of Contextual Suggestion.- Semantic and Graph-Based Models.- Exploiting Semantic Annotations for Domain-Specific Entity Search.- Reachability Analysis of Graph Modelled Collections.- Main Core Retention on Graph-of-words for Single-Document Keyword Extraction.- Entity Linking for Web Search Queries.- Sentiment and Opinion.- Beyond Sentiment Analysis: Mining Defects and Improvements from Customer Feedback.- Measuring User Infuence, Susceptibility and Cynicalness in Sentiment Diffusion.- Automated Controversy Detection on the Web.- Learning Sentiment Based Ranked-Lexicons for Opinion Retrieval.- Topic-dependent sentiment classification on Twitter.- Learning Higher-Level Features with Convolutional Restricted Boltzmann Machines for Sentiment Analysis.- Social Media.- Towards Deep Semantic Analysis of Hashtags.- Chalk and Cheese in Twitter: Discriminating Personal and Organization Accounts.- Handling Topic Drift for Topic Tracking in Microblogs.- Detecting Location-centric Communities using Social-Spatial Links with Temporal Constraints.- Using Subjectivity Analysisto Improve Thread Retrieval in Online Forums.- Selecting Training Data for Learning-based Twitter Search.- Content-Based Similarity of Twitter Users.- Specific Search Tasks.- A Corpus of Realistic Known-Item Topics With Associated Web Pages in the ClueWeb09.- Designing States, Actions, and Rewards for Using POMDP in Session Search.- Retrieving Medical Literature for Clinical Decision Support.- PatNet: A lexical database for the patent domain.- Learning to Rank Aggregated Answers for Crossword Puzzles.- Diagnose This If You Can: On the effectiveness of search engines in Finding medical self-diagnosis information.- Sources of Evidence for Automatic Indexing of Political Texts.- Automatically Assessing Wikipedia Article Quality by Exploiting Article-Editor Networks.- Temporal Models and Features.- Long time, no tweets! Time-aware personalised hashtag suggestion.- Temporal Multinomial Mixture for Instance-oriented Evolutionary Clustering.- Temporal Latent Topic User Profiles for Search Personalisation.- Document Priors Based On Time-Sensitive Social Signals.- Topic and Document Models.- Prediction of Venues in Foursquare using Flipped Topic Models.- Geographical Latent Variable Models for Microblog Retrieval.- Nonparametric Topic Modeling using Chinese Restaurant Franchise with Buddy Customers.- A Hierarchical Tree Model for Update Summarization.- Document Boltzmann Machines for Information Retrieval.- Effective Healthcare Advertising using Latent Dirichlet Allocation and Inference Engine.- User Behavior.- User simulations for interactive search: evaluating personalized query Suggestion.- The Impact of Query Interface Design on Stress, Workload and Performance.- Detecting Spam URLs in Social Media via Behavioral Analysis.-Predicting Re-Finding Activity and Diffculty.- User Behavior in Location Search on Mobile Devices.- Detecting the Eureka Effect in Complex Search.- Reproducible IR.- Twitter Sentiment Detection via Ensemble Classification Using.- Averaged Confidence Scores.- Reproducible Experiments on Lexical and Temporal Feedback for Tweet Search.- Rank-Biased Precision Reloaded: Reproducibility and Generalization.- Demonstrations.- Knowledge Journey Exhibit: Towards Age-Adaptive Search User Interfaces.- PopMeter: Linked-Entities in a Sentiment Graph.- Adaptive Faceted Ranking for Social Media Comments.- Signal: Advanced real-time information Filtering.- The iCrawl Wizard Supporting Interactive Focused Crawl Specification.- Linguistically-enhanced search over an open diachronic corpus.- From Context-Aware to Context-Based: Mobile Just-In-Time Retrieval of Cultural Heritage Objects.- Tutorials.- Visual Analytics for Information Retrieval Evaluation (VAIRE 2015).- Measuring Document Retrievability.- A Formal Approach to Effectiveness Metrics for Information Access: Retrieval, Filtering, and Clustering.- Statistical Power Analysis for Sample Size Estimation in Information Retrieval Experiments with Users.- Join the Living Lab: Evaluating News Recommendations in Real-time.- Workshops.- 5th Workshop on Context-awareness in Retrieval and Recommendation (CaRR 2015).- Multimodal Similar Case Retrieval in the Medical Domain.- Second International Workshop on Gamification for Information.- Retrieval (GamifIR).- Supporting Complex Search Tasks.- Bibliometric-enhanced Information Retrieval: 2nd International BIR Workshop.