Background and aimsConversation partner training (CPT) is an umbrella term for different approaches to intervention aiming to facilitate and improve communication between people with aphasia (PWA) and their conversation partners (CP). Some approaches are grounded in a bottom-up approach to identifying problem areas and resources in the interaction and establish learning goals in collaboration with the CP and PWA. Other approaches focus on teaching core principles (acknowledging competence, using multimodal communication support) derived from successful interactions between volunteers and PWA. General theories of communication or human interaction have not been fully explored, but may enrich CPT.MethodFour theories of communication and human interaction are explored in order to consider the relevance of specific concepts to aphasia and implications for CPT.ResultsCommunication Accommodation Theory (Giles et al. 1991) suggests that conversation participants adjust communicative behavior to adapt to their speaking partners. These “accommodations” minimize or, conversely, highlight social differences between participants. Accommodation theory offers insights that help explain the success (or not) of supported conversation in aphasia. For example, some PWA may not use communication supports when interacting with less familiar or untrained partners in order to accommodate to their unaided communication style.The main assumption of Activity-based Communication Analysis (ACA) (Allwood 2013) is that social activities have collective as well as individual influencing factors providing different conditions for communicative interaction. Actual behavior can be studied both from interactive and individual points of view. ACA especially emphasizes the analysis of interactive behavior. The linking of background factors to communicative possibilities, limitations and outcomes of different activities is the basic application of ACA that can benefit CPT.Theories of social stigma describe stigma as ‘a process by which the reaction of others spoils normal identity’ (Goffman 1963). The person possessing an undesirable attribute or behaviour, which differs from the norm or disrupts the smoothness of social encounter, may be met with aversion or fear or be considered ‘less human’. Stigmatization influences behaviour, emotions and beliefs. Stigma theory supports ‘acknowledging competence’ in CPT and promotes understanding of feelings and beliefs, which may arise when aphasia disrupts the smoothness of communicative interaction.Todres et al. (2009) describe eight interacting dimensions of humanization, which constitute a values-based framework for considering potentially humanising and dehumanising aspects of care and interactions. Philosophically informed by existential-phenomenological perspectives, the humanisation framework encourages reflection on what practices can make people feel more (or less) human. Reviewing experiences of conversation against the eight suggested dimensions of what it means to be human may offer fresh insights into the nuanced experience of being a conversation partner.Discussion The discussion focuses on how the four theories can be used in the context of CPT intervention and evaluation.Implications for clinical 
practiceThe theories provide tools for clinical practice, e.g. analysing the influence of accommodation, social activity, stigma and humanization factors.ConclusionsDrawing on theories of communication and human interaction may enrich and refine current approaches to intervention and research in CPT.ReferencesAllwood, J. (2013). A multidimensional activity based approach to communication. Wachsmuth, I., de Ruiter, J., Jaecks, P. & Kopp, S. (eds) Alignment in Communication. Amsterdam: John Benjamins. 33-55.Giles, H., Coupland, J. & Coupland, N. (1991). Accommodation Theory: Communication, context, and consequence. In Giles, H.; Coupland, J.; Coupland, N. Contexts of Accommodation. New York, NY: Cambridge University Press.Goffman, E. (1963). Stigma; notes on the management of spoiled identity. Englewood Cliffs, N.J.: Prentice-Hall.Todres, L. et al. (2009). The humanization of healthcare: a value framework for qualitative research. International Journal of Qualitative Studies on Health and Well-being; 4: 2, 68-77.