Reports an error in "The "roller coaster ride": A longitudinal investigation of the dynamic relationship between Chinese counseling trainees' self-efficacy and their clients' outcome and the mediating effects of working alliance and session evaluation" by Xu Li, Feihan Li, Chaihua Lin, Shitao Chen and Yuge Han (Journal of Counseling Psychology, Advanced Online Publication, Nov 29, 2021, np). In the article, the scale for the Working Alliance Inventory-Short Revised (WAI-SR) was incorrectly described in the Measures section as a "5-point scale that ranges from 1 to 5." The WAI-SR used the original 7-point scale ranging from 1 to 7. All versions of this article have been corrected. (The following abstract of the original article appeared in record 2022-06516-001.) Based on the social-cognitive theory, this study investigated the dynamic association between counseling trainees' self-efficacy and their clients' outcome (i.e., symptom distress), and the mediating effects of therapist- and client-rated working alliance and session quality. Data set included 1,352 sessions conducted by 87 master's level therapist trainees with their 317 clients in China. Before every session, therapists completed a measure of self-efficacy and clients reported their symptom distress; and after every session, both therapists and clients rated their working alliance and session quality. Results showed that, (a) over the course of therapy, the initial level of therapist self-efficacy did not predict how quickly client symptom declined; (b) the initial level of client distress did not predict how quickly therapist self-efficacy increased; and (c) client distress decline was not related to therapist self-efficacy increase over the course of therapy. However, at the session-to-session level, higher therapist self-efficacy before one session significantly predicted lower client distress before the next session, and higher client distress before one session significantly predicted lower therapist self-efficacy before the subsequent session. Therapist and client perceptions of working alliance were both significant mediators, while their session quality ratings were not. Findings supported the dynamic and reciprocal relationship between therapist self-efficacy and client distress at the immediate session-to-session level rather than the overall trajectory level, and revealed its specific mediating mechanism through the relationship building between therapist and client. (PsycInfo Database Record (c) 2022 APA, all rights reserved).