Examining therapist estimation of client working alliance and client symptom outcome using truth and bias model and response surface analysis.

Objective: The aims of this study were to investigate the congruence and discrepancy between Chinese therapist trainees' estimated client working alliance (WA) and their clients' actual WA rating, and how the congruence and discrepancy predicted client symptom outcome.

Methods: Participants were 211 beginning therapist trainees and 1216 clients. Data from their 6888 sessions were analyzed using Truth and Bias Model and Response Surface Model.

Results And Conclusions: (i) Chinese trainees' estimation of client WA was on average significantly lower than actual client WA. (ii) At the between-person level, whether the trainee generally over- or underestimated client WA was not related to the client's initial symptom level or symptom improvement rate. (iii) At the within-person between-session level, a session where a trainee accurately perceived high client WA, compared to a session where the trainee accurately perceived low client WA, was followed by greater client symptom relief before the next session. In the case of estimation bias, a session where the trainee underestimated client WA was followed by greater client symptom reduction in the next session, rather than the other way around when the trainee overestimated client WA. Implications on therapist training were discussed.