Understanding users 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. Needs Inquiry (需求探索 DS5102, with Prof. Yeh, Yi-Yu and Prof. Yueh, Hsiu-Ping) 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 user behaviors and performance, follows by introduction of the concepts and techniques of understanding needs, needs analysis, and needs inquiry. Finally the course concludes by a capstone project of user study. Examples of designs and design treatments are given to illustrate principles and advice, accompanied by critical reflection.