An approach to socio-technical HCI called Human Work Interaction Design (HWID) emerged around 2005. It has grown steadily, and now is the time for sharing this research with a wider audience. In this book, the HWID approach is used to discuss socio-technical HCI theory, cases, methods, and impact. The book introduces HWID as a multi-sided platform for theorizing about socio-technical HCI work design in the digital age. It presents design cases that illustrate the design of socio-technical relations, provides specific advice for researchers, consultants, and policy makers, and reflects on the open issues related to theorizing about sociotechnical HCI. The benefits of HWID include that it meets the requirement of taking both the social and the technical into account, while focusing strongly on the relationship between the social and the technical. In addition, it is truly international and explicitly considers local cultural, organizational, and technological contexts.