Information Retrieval Technology

Asia Information Retrieval Symposium (AIRS) 2009 was the ?fth AIRS conf- ence in the seriesestablished in 2004.The ?rst AIRS washeld in Beijing, China, the second in Jeju, Korea, the third in Singapore and the fourth in Harbin, China. The AIRS conferences trace their roots to the successful Information Retrieval with Asian Languages (IRAL) workshops, which started in 1996. The AIRS series aims to bring together international researchers and dev- opers to exchange new ideas and the latest results in information retrieval. The scope of the conference encompassed the theory and practice of all aspects of information retrieval in text, audio, image, video, and multimedia data. AIRS2009received82submissions,fromwhichwecarefullyselected18regular papers(22%)and20(24%)postersthroughadouble-blindreviewingprocess.We are pleased to report that the conference proceedings include contributions from not only Asian countries,but also from Finland, Italy, Australia,UK and USA. We are grateful to Elizabeth Liddy, chair of ACM SIGIR, for accepting to be the honorary conference chair, and to Hokkaido University for hosting the c- ference. We thank the Information Retrieval Facility, Microsoft Research Asia, Ricoh, Ltd., Global COE Program "Center for Next-Generation Information TechnologyBasedonKnowledgeDiscoveryandKnowledgeFederation" andS- poro International Communication Plaza Foundation for sponsoring the conf- ence, and Springer for publishing the conference proceedings as part of their Lecture Notes in Computer Science (LNCS) series. We also thank ACM SIGIR and IPSJ SIGFI for giving the conference an "in cooperation with" status.