Evidence based on internal structure of the Brazilian version of ABAS-3 parents forms

Adaptive behavior assessment is crucial for understanding individuals' functional abilities. The Adaptive Behavior Assessment System-Third Edition (ABAS-3) is widely used for this purpose, but its internal structure requires validation in different cultural contexts. This study examined the internal structure validity evidence of the Brazilian Portuguese version of the ABAS-3 using item-level data. To evaluate the factor structure of the Brazilian Portuguese version of the ABAS-3 Parent Forms and determine the best-fitting model for assessing adaptive functioning. A total of 2594 children from both public and private schools in Brazil, ranging from preschoolers to school-aged individuals, were assessed through parent reports using the Brazilian Portuguese versions of Parent/Primary Caregiver Form/Ages 0-5 and Parent Form/Ages 5-21. Confirmatory factor analyses were conducted to test three models: a three-factor model, a three-factor-plus-general-factor model, and a single general factor model. Hierarchical structures were considered to determine the most appropriate factor solution. The findings supported the validity of the three-factor model (conceptual, social, and practical domains) and three-factor-plus-general-factor model. The latter provided the best fit, allowing for both domain-specific and general adaptive functioning score interpretations. This model aligns with the theoretical framework of adaptive functioning according to the three domains (conceptual, social, and practical). The Brazilian Portuguese version of the ABAS-3 Parent Forms demonstrates strong internal structure validity, supporting its use in assessing adaptive functioning in Brazilian children. The results reinforce the suitability of this instrument for clinical and research applications.