Reliability and preliminary insights of adapting the Working Alliance Inventory Observer form for Bahasa Indonesia psychotherapy settings

Working alliance is a key predictor of therapy outcomes, and observer ratings offer an objective perspective. This study adapted the Working Alliance Inventory-Observer Form (WAI-O) for Bahasa Indonesia psychotherapy settings. It involved 15 therapist-patient dyads and three expert observers. The study correlated third-session WAI-O scores with sixth-session therapist-rated improvements for predictive validity and with WAI-client and WAI-therapist scores for construct validity. The Indonesian WAI-O demonstrated moderate predictive validity, no significant convergent validity, and excellent reliability, with a Cronbach’s alpha of 0.994 and an ICC of 0.628. Preliminary evidence supports the Indonesian WAI-O’s reliability and potential validity for predicting overall clinical improvement, but further research with a larger sample size is suggested to fully establish its validity.