His research interests are information retrieval, personal data analytics and lifelogging. Lifelogging integrates personal sensing, computer science, cognitive science and data-driven healthcare analytics to realize the next-generation of digital records for the individual. He has co-authored more than 200 publications in the area of multimedia data analytics and he is the founder of the Lifelog Search Challenge, as well as the NTCIR-Lifelog task and ImageCLEF-Lifelog.