WSDM (pronounced "wisdom") is a brand new ACM conference intended to be complementary to the World Wide Web Conference tracks in search and data mining. The pace of innovation in these areas has reached a level that requires more than one premier annual venue. WSDM invites original, high quality submissions related to search and data mining on the Web, with an emphasis on practical but principled novel models, algorithm design and analysis, economics implications, and in-depth experimental analysis of accuracy and performance.