“…As noted by Elliott (2010), HP researchers have been distinctive in their focus on change processes within and across HP treatments. Indeed, many innovative genres of HP change process research have emerged over the last quarter century to enrich our clinical understanding of how change happens in effective HP treatments, including helpful aspects of therapy post-session inquiry (Elliott & James, 1989), comprehensive process analysis (Elliott, 1989), conversational analysis (Muntigl et al, 2013;Sutherland, Peräkylä, & Elliott, 2014), process-outcome quantitative and qualitative research investigations (Angus, Goldman & Mergenthaler, 2008;Cooper, Watson, & Höll-dampf, 2010), measure development (Wiggins, Elliott, & Cooper, 2012), and systematic case studies (McLeod, 2010;Angus & Kagan, 2013). In particular, humanistic therapy researchers have investigated three key mechanisms of change that cohere closely with HP practice principles (Elliott et al, 2013): they focus on the development of productive therapeutic relationship, therapist empathy, heightened client experiencing, and emotional/experiential engagement in therapy sessions.…”