Extended Reality (XR) is uniquely capable of spatial and embodied simulations for various modes of worlds, beings, and relations, which makes it a medium especially well suited to exploring, realizing, and advancing posthuman/more-than-human HCI agendas. However, the three major domains of HCI research on XR---space, body, and interaction---have largely been shaped by anthropocentric design assumptions that prioritize perceptual fidelity, human-like representation, and instrumental control. This paper argues for a critical reorientation beyond these norms by shifting the direction for the domains: the design of XR environments as speculative worlding; embodiments as distributed decentering; and enactments as entangled becoming. It further recognizes XR and posthuman/more-than-human HCI to be mutually enabling, and proposes a co-constitutive framework where they can both evolve as the three domains continuously shape one another. Its contribution is a conceptual provocation that provides a diagnostic vocabulary and schema to reinvent XR as a site for cultivating speculative, inclusive, and transformative futures through HCI research.
ACM CHI Conference on Human Factors in Computing Systems