Introduction to the special issue on the 50th anniversary of IJHCS.

This special issue celebrates the 50th anniversary of the International Journal of Human-Computer Studies (IJHCS), which published its first volume in January 1969. The special issue comprises 15 contributions from a number of experts in Human-Computer Interaction (HCI) and other areas relevant to IJHCS. These contributions are best characterized as ‘landscape papers’, providing insightful analyses about the evolution (i.e., the past, the present and the future) of research areas relevant to IJHCS. The areas covered in this special issue include: the history and scope of the journal; foundational concerns in HCI; critical discussions about the issues surrounding digital living in a variety of areas, from healthcare and cybersecurity to digital games and art; the making of interactive products and services, as seen through the viewpoints defined by research in psychology of programming, end-user development and participatory design; and, finally, the issues associated with adapting to various novel emerging technologies, including automated systems, online personalisation, human augmentations, mixed reality, and sonic interfaces. In this short essay, we introduce the special issue, reflecting on the nature and evolution of the journal, before providing short outlines of each of the contributions to this special issue.