This class introduces students to the field of human-computer interaction (HCI) and user interface design. Specifically, the course covers the following topics: Fundamental characteristics of human cognition, such as reaction time, rules of perception, and memory performance Models of interaction between people and their environment, such as affordances, mappings, constraints, slips, and mistakes Milestones in the history of human-computer interaction Principles of iterative design User interface prototyping techniques User studies and evaluation methods Golden rules of user interface design User interface design notations After this class, students will know how user interfaces have been developed over the past decades, and what constants of human performance need to be considered when designing them. This class forms the basis for the classes “ Designing Interactive Systems II ” (which looks at more technical aspects of user interface development) and “ Current Topics in HCI and Media Computing ”, as well as the “ Post-Desktop User Interfaces ” seminar and other courses from our research group. Students will be able to apply iterative design, prototyping, and evaluation methods to design usable, appropriate user interfaces in a user-centered fashion. All assignments are group assignments to foster collaboration skills, and project-based to strengthen project planning, conflict management and presentation skills. Learning to think in designers' terms is a crucial competence for computer scientists working on user interfaces, a job that requires collaboration in interdisciplinary teams.