Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition marked by persistent challenges in language acquisition, particularly in the lexical and semantic domains. This study examined the effectiveness of an adapted Applied Behavior Analysis (ABA) intervention in improving lexical and semantic language skills among preschool-aged children with ASD. A total of 3- to 6-year-old children participated, divided into experimental and control groups across two specialized centers. The experimental group received an adapted ABA-based program emphasizing discrete trial teaching, functional communication strategies, visual supports, and targeted reinforcement techniques. Pre- and post-intervention assessments were conducted using a structured methodology that evaluated active and passive vocabulary, semantic categorization, and contextual language use. Results from paired t-tests showed statistically significant improvements in the experimental group compared to the control group (p < .05). Despite these gains, generalization of language skills across social contexts remained limited. These findings highlight the value of individualized behavioral interventions and support their inclusion in early childhood programs for children with ASD.