A promising line of research to improve the general effectiveness and efficacy of psychotherapy and to reduce dropout is to focus on the investigation of alliance formation and repair of alliance ruptures. This study draws upon five essential components: (1) focus on interpersonal process; (2) the collection of continuous data (i.e. from each therapy session); (3) collection of continuous data from multiple perspectives, i.e. both from patient and therapist after each session, and digital recordings makin g external observation possible; (4) the combination of qualitative and quantitative data; (5) the study of expert therapists. In addition to focus on alliance formation, maintenance, rupture and repair, the actual sub-studies will follow significant (pos itive and negative) change events and critical incidences. Approximately 15 expert therapists of different theoretical orientations will collect data and record interactions from naturalistic therapies with clients (including clients that are typically co nsidered 'difficult to treat', including therapies of various duration) in outpatient settings. The chosen protocol structure reflects measurement domains common in contemporary psychotherapy research: Common therapy outcome, Therapy process, Client/Thera pist pre-therapy background (including diagnostic assessment of clients). The analytical pathways will be explored when the researchers in each sub-study will direct themselves from the standardized measurements as indicators to actual selection of cases and sessions. The analyses will all be conducted in ways that start out with existing knowledge of relationships, and contribute with answers to the questions about dynamics and mechanisms. The general move is then, from questions about what matters to t he questions about how this matters and why that is so. The principal researchers all belong to a research group on Clinical Psychology - Psychotherapy and development at Department of Psychology at the University of Oslo. The study will also rest on esta blished collaboration with three researchers form US.