Training to code therapeutic interactions in Functional Analytic Psychotherapy: The utility of a video-based Behavior Skills Training

Background: Coding therapy sessions is essential for evaluating treatment fidelity and understanding in-session mechanisms of change. However, coder training often lacks standardized, replicable methods and is resource intensive. Objective: This study evaluated the effectiveness of a video-based Behavioral Skills Training (BST) protocol to teach precision coding of Functional Analytic Psychotherapy Rating Scale (FAPRS) codes during brief clinical interactions (vignettes). Design and methods: A randomized nonconcurrent multiple baseline design across five master's degree students was employed, including generalization and follow-up phases. BST was delivered in two components: (a) video-based instruction (v-INS) and (b) video-based modeling, rehearsal, and performance feedback (v-MRF). Participants were required to achieve a mastery criterion of 90 % precision coding during training. Results: Four of the five participants demonstrated significant improvements in coding precision following video-based BST. Precision generalized to novel clinical vignettes and was maintained at follow-up. Between-case standardized mean differences showed large effect sizes, indicating meaningful improvements in coding accuracy. Conclusions: Video-based BST was effective, time-efficient, and well-accepted for training coding skills in FAP, with participants achieving mastery during training. However, precision levels during post-training phases remained below the 90 % criterion for some participants. Future research should explore the use of booster sessions and extended training phases to enhance the maintenance and generalization of coding precision.