The purpose of this study was to develop a script-based intervention program using video modeling to improve communication in café customer-service situations for adults with developmental disabilities and to examine the effectiveness of this program...
The purpose of this study was to develop a script-based intervention program using video modeling to improve communication in café customer-service situations for adults with developmental disabilities and to examine the effectiveness of this program. The research questions were as follows: (1) to develop a script-based intervention program using video modeling for adults with developmental disabilities in café customer-service situations; and (2) to investigate the effects of this program on the communication abilities of adults with developmental disabilities, specifically their core vocabulary and communication functions. To address these questions, differences in core vocabulary and communication functions between groups were examined, and within-group differences across pre-, post-, and maintenance assessments were analyzed. To construct the program, previous studies on script-based intervention and video modeling—both evidence-based approaches—were reviewed. Literature related to barista roles and customer-service interactions was analyzed to develop the program content. Following expert validity review, a preliminary version of the program was developed. A pilot study was then conducted with four adults with developmental disabilities over 17 intervention sessions, after which the program was revised and finalized.
A total of 24 adults with developmental disabilities aged 19 to 39 years participated in the study and were assigned to an experimental group, a comparison group, or a control group. The experimental group received the newly developed script-based intervention using video modeling in café customer-service contexts. The comparison group received intervention using picture cards focusing on vocabulary and sentence expression with the same thematic content, while thecontrol group received no intervention.
Screening assessments included a language test (PK-WAB-R), a vocabulary test (REVT), a nonverbal intelligence test (K-CTONI-2), the Autism Diagnostic Interview–Revised (ADI-R), and the Communication Matrix. A Kruskal–Wallis test was conducted to confirm homogeneity among the three groups. Core vocabulary responses were scored as follows: correct responses (2 points), correct responses after semantic cues (1 point), and incorrect responses (0 points).
Communication functions—greeting, calling, responding, requesting information, requesting actions, and making objective comments—were scored as correct (1 point) or incorrect (0 points). The effects of the script-based intervention using video modeling were as follows. First, there were statistically significant differences among the three groups in both core vocabulary (χ² = 14.260, p < .05) and communication functions (χ²= 9.023, p < .05), with the experimental group showing higher mean ranks in both areas. Pairwise comparisons of pre–post change scores indicated that the experimental group demonstrated significantly greater improvement than the comparison group in communication functions (Z = –3.162, p < .017), and significantly greater improvement than the control group in both core vocabulary (Z= –3.376, p < .017) and communication functions (Z = –3.366, p < .017).
However, no significant differences were found between the experimental and comparison groups in core vocabulary (Z = –2.158, p > .017), greeting (Z = –1.916, p > .017), or calling (Z = –1.697, p > .017). The experimental group showed higher mean ranks particularly in requesting information, requesting actions, responding, and making objective comments, with marked improvement in responding and objective commenting.
Second, within-group analyses revealed statistically significant differences across pre-, post-, and maintenance assessments in both the experimental and comparison groups, indicating that intervention effects were maintained. In particular, the experimental group showed large and sustained improvements in core vocabulary (χ² = 13.867, p < .05) and communication functions (χ² = 13.067, p < .05). This study developed a script-based intervention program using video modeling for adults with developmental disabilities and verified its effectiveness through group comparisons. Unlike previous studies, which primarily focused on children with small sample sizes, this study targeted adults and employed a group-comparison design, contributing to the literature on adult intervention research. By demonstrating improvements and maintenance in both core vocabulary and communication functions, the study highlights the potential for enhancing communication abilities among adults with developmental disabilities. Given the ongoing scarcity of communication-support interventions for this population, the development and practical application of a vocationally relevant program—such as café customer-service training—holds meaningful implications for expanding communication support in adulthood.