Efficacy of the Korean PEERS® for Preschoolers (PEERS®-PS-K) Social Skills Intervention: A Randomized Controlled Trial for Children With Autism Spectrum Disorder

Inclusion Criteria: * Children aged 4 to 6 years (at least 4 years 0 months and less than 7 years diagnosed with Autism Spectrum Disorder (ASD) through standardized diagnostic tools(K-ADOS-2 / K-ADI-R). * Verbal Intelligence Quotient (VIQ) of 70 or higher on the Korean Wechsler Preschool and Primary Scale of Intelligence (K-WPPSI). * Native Korean speakers with sufficient verbal fluency to communicate in full sentences appropriate for their age. * Capable of participating in group activities and language-based interventions as determined through a screening procedure. * Parents or legal guardians who understand the study's purpose and provide voluntary informed consent for both themselves and their child. Exclusion Criteria: * Parents or legal guardians who do not consent to their child's participation in the study. * Presence of intellectual disability or other comorbid psychiatric conditions that may interfere with study participation. * Children exhibiting clinically significant challenging behaviors that could disrupt group sessions. * Other clinically significant neurological, medical, visual, or hearing impairments.