THE EFFECTIVENESS OF AN ACTIVE SUPPORT PROGRAM ON PRESCHOOL TEACHERS’ PROFESSIONAL PRACTICE IN SUPPORTING LATE-TALKING TODDLERS AGED 18-36 MONTHS IN INCLUSIVE CLASSROOMS

This study examines the effects of an active support program on preschool teachers’ professional practice in supporting late-talking children aged 18–36 months in inclusive classrooms in Vietnam. To address the limited empirical evidence on teacher-level outcomes in early language intervention, a quasi-experimental pretest–posttest design was used with 30 preschool teachers across 06 preschools in Hanoi. Data was collected using a structured questionnaire, complemented by additional sources of information to enhance the validity of the assessment of teachers’ awareness, knowledge of responsive interaction strategies, and classroom practices. Paired-samples T-tests and effect size analyses were conducted. The findings shown statistically significant improvements across all three dimensions. Teachers demonstrated enhanced understanding of late language development, increased knowledge of interaction-based strategies, and more frequent use of intentional one-to-one interactions. Effect sizes ranged from large to very large, indicating substantial practical significance. The results support interaction-based and ecological intervention frameworks, highlighting the central role of teachers as key agents in facilitating meaningful participation and early communication. This study provides empirical evidence for the scalability of active support programs within early childhood education in Vietnam.