This book constitutes the refereed proceedings of the 23rd China Conference on Information Retrieval, CCIR 2017, held in Shanghai, China, in July 2017. The 21 full papers presented were carefully reviewed and selected from 41 submissions. The papers are organized in topical sections: recommendation; understanding users; NLP for IR; IR and applications; query processing and analysis.

This book constitutes the refereed proceedings of the 12th Information Retrieval Societies Conference, AIRS 2016, held in Beijing, China, in November/December 2016. The 21 full papers presented together with 11 short papers were carefully reviewed and selected from 57 submissions. The final programme of AIRS 2015 is divided in the following tracks: IR models and theories; machine learning and data mining for IR; IR applications and user modeling; personalization and recommendation; and IR evaluation.