Refining Clinical Attitudes in Trainee Clinical Psychologists: A Bayesian Longitudinal Study of Supervision-Based Training

This study examined the refinement process of clinical attitudes in trainee clinical psychologists through supervised trial counseling (N = 3). Clinical attitudes (zM) were operationalized as a composite index created by standardizing and integrating scores from the FMS-R (Uenishi, 2011), the EPS (Hayama et al., 2008), and the EESR (Kakuta, 1994) across 15 weeks. Bayesian linear regression showed that changes in zM reflected cumulative time-based progression (week) rather than short-term autoregressive effects (lag₁) between sessions. Bayesian repeated-measures ANOVA provided “decisive” evidence that the phase model best accounted for the progressive refinement of zM across the early, middle, and late phases. Furthermore, all phaseto- phase comparisons yielded “strong” to “decisive” evidence, exceeded the minimal clinically important difference (MCID; d ≥ 0.50), excluded zero in their 95% CIs, and showed “large” effects. Taken together, these findings indicate that the training model adopted in this study is an effective means of facilitating the refinement of clinical attitudes, with effects supported as both statistically credible and clinically meaningful. However, the absence of pre- and post-training baseline data limits causal inference. Future research should employ designs such as ABA protocols to more rigorously examine the refinement of clinical attitudes and the effectiveness of the training model, thereby strengthening the empirical foundation of clinical training for trainee clinical psychologists.