Comparative Outcomes of VR and In-person NDBI-informed Social Skills Interventions for Preschool-aged Children With Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by differences in social interaction and communication, along with restricted or repetitive behavior patterns (American Psychiatric Association, 2022). These developmental differences typically emerge in early childhood and significantly impact early developmental trajectories and continue to affect individuals throughout life (Lord et al., 2018). Over the past two decades, the global prevalence has risen considerably, based on 2022 surveillance data from the U.S. Centers for Disease Control and Prevention (CDC) indicating that one in 31 eight-year-old children received an ASD diagnosis, almost a fivefold increase since 2002 (Shaw et al., 2025), not only reflecting improved diagnostic practices and greater societal awareness of early developmental differences (Maenner et al., 2023), but also highlights the need to support worldwide autistic individuals (Zeidan et al., 2022).

Social communication difficulties represent one of the most impactful challenges for autistic children (Kasari & Rotheram-Fuller, 2007), and are associated with downstream consequences in academic functioning, peer relationships, and mental health (Bellini et al., 2007). A substantial proportion of autistic children have age-appropriate cognitive or language abilities, yet still display marked difficulties in social cognition, play skills, and emotion regulation (Lee & Park, 2007; Liss et al., 2001). Differences in social engagement between autistic children with age-appropriate cognitive abilities and their typically developing peers become increasingly apparent during early childhood, including lower frequency of peer interaction, challenges in interpreting social cues, and difficulties maintaining conversations (McConnell, 2002; Barry et al., 2003). These challenges often become more pronounced upon school entry, when social demands increase and unstructured peer interactions become more complex (Koegel et al., 2013). Thus, preschool social skills intervention is viewed as a critical strategy for preventing later social isolation and school adjustment difficulties (Barnhill, 2007; Dawson et al., 2010; Landa, 2008).

Group-based social skills interventions are frequently used in early-intervention and clinical settings because they offer natural peer contexts, opportunities for observational learning, and embedded practice within dynamic social routines. (Barry et al., 2003; Capes et al., 2019; Gates et al., 2017). Systematic reviews and randomized trials report moderate effects for group-based social interventions for young autistic children (Freitag et al., 2016; Gates et al., 2017; Wolstencroft et al., 2018). Despite these benefits, many existing programs rely on discrete, theme-based instruction structures that target one skill at a time and often incorporate didactic teaching (Kasari et al., 2015; Radley et al., 2020; Tripathi et al., 2022). Such formats may limit opportunities for repeated, contextualized practice and may reduce flexibility in responding to children's moment-to-moment social engagement, constraining generalization and maintenance of gains (Babb et al., 2020). Access to early social-communication intervention is also inconsistent across regions and service systems, particularly in settings facing clinician shortages or limited availability of structured group programs. (Stahmer et al., 2005; Vismara & Rogers, 2010). These challenges underline the need for feasible, ecologically valid intervention models that can increase children's opportunities for naturalistic social learning.

Two emerging approaches may address these challenges. Virtual reality (VR), particularly through head-mounted displays (HMDs), has become a promising platform for delivering social and communication skill interventions to autistic individuals (Karami et al., 2021). VR provides immersive, structured, and engaging environments in which autistic individuals can practice social scenarios with reduced real-world unpredictability (Parsons & Cobb, 2016; Wallace et al., 2017). A systematic review has demonstrated that VR-based interventions can enhance attention, social skills, emotional skills, and communication abilities (Mesa-Gresa et al., 2018). In parallel, Naturalistic Developmental Behavioral Interventions (NDBIs) have become one of the most well-established evidence-based approaches for young autistic children, integrating developmental principles and applied behavior analysis within child-led, context-embedded activities that support social engagement, emotional regulation, and flexible learning across related skill domains (Sandbank et al., 2020; Schreibman et al., 2015). NDBIs have been adapted into group formats to enhance ecological validity and cost-effectiveness, while providing more opportunities for peer interaction and naturalistic social learning (Tiede & Walton, 2019; Vivanti et al., 2017). Integrating NDBIs principles into VR may be particularly valuable, as VR environments can embed naturalistic interaction opportunities while maintaining consistency and controllability. However, empirical applications of NDBI-informed approaches within VR remain limited (Dechsling et al., 2022). To address this gap, our interdisciplinary research team developed an NDBI-informed VR social-skill intervention program for autistic preschool children without intellectual disabilities (ID), featuring immersive play-based scenarios and dynamic prompting tailored to children's behavioral cues (Wu et al., 2023; NSTC 112-2218-E-008-016). Preliminary single-group findings suggested improvements in children's social behaviors (Lin et al., 2024).

Although VR offers consistency and high practice density, its interactions remain constrained by preprogrammed structures. In contrast, in-person group programs allow clinicians to provide highly flexible, moment-to-moment adjustments in response to children's spontaneous behaviors and peer dynamics. Recent reviews indicate the scarcity of direct comparisons between VR-based interventions and equivalent in-person social-skills group programs, leaving it unclear whether the two modalities produce comparable therapeutic benefits (Dechsling et al., 2021). Understanding these differences is critical for determining how alternative delivery formats support engagement and learning in early intervention contexts, particularly as service systems explore more flexible or scalable models of intervention (Simacek et al., 2021). Building upon this rationale, the present study compares two delivery modalities: (1) the VR-HMD system and (2) an in-person, clinical psychologist-led group intervention directly adapted from the VR curriculum. The in-person version retained the session structure and therapeutic principle of the original VR curriculum, allowing a direct comparison of delivery format. In addition, because social-communication skills may be expressed differently across home and school contexts, the present study incorporated both caregiver and teacher reports to capture cross-contextual outcomes and informant-specific patterns, and to compare outcomes and clinical utility between VR-mediated and in-person group interventions to inform flexible and scalable service models for autistic preschoolers without ID.