The second workshop on Theory-Informed User Modeling for Tailoring and Personalizing Interfaces (HUMANIZE) took place in conjunction with the 23rd annual meeting of the intelligent user interfaces (IUI) community in Tokyo, Japan on March 11, 2018. The goal of the workshop was to attract researchers from different fields by accepting contributions on the intersection of practical data mining methods and theoretical knowledge for personalization. A total of eight papers were accepted for this edition of the workshop.