"Where is the relationship" revisited: Using actor-partner interdependence modeling and common fate model in examining dyadic working alliance and session quality.

Building on previous studies (e.g., Kivlighan, 2007), we explored the application of actor-partner interdependence modeling (APIM) and the common fate model (CFM) in a multilevel framework to examine the dyadic multilevel associations between therapists' and clients' perceptions of working alliance and session quality. Forty-four therapists and their 284 adult community clients completed measures of working alliance and session quality after every session (a total of 8,188 sessions included in this study). We used APIM to unravel the mutual interdependence between therapist and client perceptions and used CFM to model both the shared and individual perceptions of the therapists and clients. APIM analyses showed that, at the between-session level, therapist and client perception of the session quality each was significantly predicted by the other's perception of the working alliance. At the between-client level, only therapist perception of the session quality was significantly predicted by the client's perception of the working alliance. There were no significant partner effects at the between-therapist level. CFM analyses showed that therapist-client shared perceptions of working alliance significantly predicted their shared perception of session quality at all three levels. In contrast, individual perceptions of working alliance correlated with individual perceptions of session quality for therapists only at the between-therapist and between-session levels, and for clients only at the between-client and between-session levels. Theoretical, methodological, and practical implications are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).