論文アブストラクト：HCI is focused on improving the interactions we have with technology and innovating new types of interactions, as well as expanding the types of people for whom those interactions are designed. Central to these efforts is the simultaneously empowering and contested construct of the "user." This paper examines what the construct of the user highlights, as well as what it conceals. We introduce post-userism, a perspective that simultaneously acknowledges the limits of, and proposes alternatives to, the central construct of the user as proxy for the "human" in HCI. Drawing on developments across the historical trajectory of HCI, we articulate how the user is enacted across four different levels of representation-systems, interface, design process, and the ideology and identify situations where the user breaks down. Synthesizing prior work, we offer a series of strategies for grappling with such situations. In doing so, we seek to overcome the limitations imposed by the user and develop a language that will aid in evolving the foundations of HCI by asking what, exactly, we place at the center of our scholarship and design.