What can design practices, engagement and participation become if we assume multiple ontologies, radical difference and pluralism? What happens, for instance, if established conceptions and rationalities of design and participatory research practices are exposed to a multinaturalist Amerindian ontology that implies that those with whom we study and engage see the world in the same way as we do only from different bodies? (de Castro, 1998; 2004) So, instead of inhabiting the same world, but having multiple cultures, we inhabit different worlds, but have the same culture. So, for instance in such an ontology what the designer, may see as a technological tool to aid the practice, may for the practice not be a tool, but a work load. Multinaturalism implies that we cannot take for granted a shared world and this entail that we must work harder practically and conceptually to come to inhabit the ontology of the other – and potentially invent and construct common worlds.  
In accordance with the speculative and ontological turn(s), this session invites papers that speculate and experiment with such ideas and consider the consequences for design and participatory research practices (Heywood, n.d.; Jensen, 2010; Martin & Heil, 1999; Mol, 2002; Pickering, 2017; Wilkie et al., 2017). The overall ambition with such speculations and experiments is to explore and enable thinking, researching and acting differently: the care for the possible this entails and the commitment to taking seriously the production of existence and knowledges that might take place as part of participatory research practices.
The ontological and speculative turn entails the appreciation of worlds as constructed through interwoven material and conceptual practices and implies the dissolution of both nature/culture and cognitive/material oppositions. The work of Marilyn Strathern, Eduardo Viveiros de Castro, Bruno Latour, Annemarie Mol and Isabelle Stengers is central to the ontological turn and has proposed concepts such as dividualism, praxiography and multinaturalism (ibid). According to de Castro the ontological turn defamiliarizes and de-colonialises modernist and western ontological presumptions about nature-culture, human-non-human divisions. And as both de Castro and Jon Bialecki argue the ontological turn should not be taken – as some might read it – as a critique of one failed ontology (the western) and its replacement with another (say an ontology of sociomaterial interwovenness), since this would just be yet another modernist move. The point is, rather, and in line in with Deleuze and Guattari’s (1987: 28) empirical transcendentalism, to “overthrow ontology” altogether.
References
de Castro, E. (1998). Cosmological Deixis and Amerindian Perspectivism. The Journal of the Royal Anthropological Institute, 4(3), 469–488.
De Castro, E. V. (2004). EXCHANGING PERSPECTIVES The Transformation of Objects into Subjects in Amerindian Ontologies. Common Knowledge, 10(3), 463–484.
Deleuze, G., & Guattari, F. (1987). A thousand plateaus: Capitalism and schizophrenia. Univ of Minnesota Pr.
Heywood, P. (n.d.). Ontological Turn, The. . . ISSN, 12.
Jensen, C. B. (2010). Ontologies for Developing Things: Making Health Care Futures Through Technology. Sense Publishers.
Martin, C. B., & Heil, J. (1999). The ontological turn. Midwest Studies in Philosophy, 23(1), 34–60.
Mol, A. (2002). The body multiple: Ontology in medical practice. Duke University Press.
Pickering, A. (2017). The Ontological Turn: Taking Different Worlds Seriously. Social Analysis, 61(2). https://doi.org/10.3167/sa.2017.610209
Wilkie, A., Savransky, M., & Rosengarten, M. (Eds.). (2017). Speculative research: The lure of possible futures. Routledge Taylor & Francis Group.