Abstract
School-based assessment of social adaptation often relies on either student self-reports or teacher judgements, whereas the integration of these sources remains methodologically underdeveloped, especially in bilingual settings. This study examined whether an integrated pedagogical and psychometric framework can support the assessment of Grade 5 students’ social adaptation in Kazakh- and Russian-medium schools. A multisite cross-sectional design was used with 458 Grade 5 students from five schools in Almaty and independent teacher ratings for external validation. The School Social Adaptation Scale (SSAS) was evaluated for internal consistency, factor structure, and measurement invariance across language of instruction and gender; convergent validity was examined against the Teacher Social Adaptation Rating (TSAR). The SSAS showed strong total-scale reliability ( α = ω = 0.910), a stable five-factor structure, and scalar invariance across language and gender. Self-reported adaptation was positively associated with teacher ratings (b = 0.504, SE = 0.046, p < .001). The results support the use of the SSAS as a reliable and comparable instrument for bilingual school settings and indicate that combining student self-reports with independent teacher ratings strengthens the interpretability of school-based social adaptation assessment.