User experience has evolved as a new area of Human Computer Interaction research, and is taken as critical element that bridges the system design and the user performance. User Behavior Research (使用者行為研究 126D1030 / LIS8025) explores the design process for user experience and engagement, which expands the traditional concept of usability and utility in design to include elements of aesthetics, fun and excitement that are directly related to users’ behaviors and intentions. The course starts by reviewing the background knowledge of human in human-computer interaction, follows by introduction of the methodological design of a user behavior research with revisiting the trends and issues of user experience research, and finally concludes by conducting a research project. Examples of designs and design treatments are given to illustrate principles and advice, accompanied by critical reflection.