This textbook goes through the complete cycle of HCI design and implementation, explaining the core HCI concepts behind each step. Illustrating the entire development cycle of an interactive software product, it starts by reviewing the fundamentals of HCI. Next, it delves into the application of this knowledge. It covers the forming of HCI requirements, modeling the interaction process, designing the interface, implementing the resulting design, and evaluating the implemented product. The book includes lecture slides and source code for the example applications.