He is widely interested in data mining, machine learning, information retrieval and their applications to the Web, natural language, social networks, and health informatics. He is a recipient of the NSF CAREER Award and multiple best paper awards at ICML, KDD, WSDM, and other related venues. He has co-chaired multiple research tracks of the WWW conference, has served on the editorial boards of multiple top journals, and is the general co-chair of SIGIR 2018.