Assessing therapist development: Reliability and validity of the Supervisee Levels Questionnaire (SLQ‐R)

BACKGROUND: Therapist development is a crucial target for clinical training in order to ensure high-quality psychotherapy. A major challenge in examining therapeutic development is the assessment of developmental processes. The Supervisee Levels Questionnaire (SLQ-R) was analyzed in this study to examine its validity, reliability, and underlying dimensional structure. METHOD: Seven hundred and sixty therapists participated in an online survey concerning their current psychotherapy training. The factor structure as well as the validity of the SLQ-R were investigated using exploratory and confirmatory factor analysis. RESULTS: In line with the results of the exploratory factor analyses, a Bifactor ESEM (exploratory structural equation modeling) model with two factors and one global factor provided the best fit to the data. The two factors were labeled professional self-confidence and professional insecurity. CONCLUSION: Empirical support for reliability and validity of the new factor structure of the SLQ-R was found. The instrument is useful for assessing the therapist's developmental level.