Involving users in the design of systems has been a byword in HCI since its inception. The nature and depth of this involvement has varied from identifying needs and requirements to imagining solutions and evaluating outcomes. As different disciplinary perspectives and values have been brought to bear on the design of interactive systems, how user involvement has been understood and configured has also varied. Most recently we are becoming accustomed to working with terms like human-centered design, experience-centered design, participatory design, and co-design, which represent the range of different viewpoints and value systems at play in HCI design research. (acm.org)