Exploratory factor analysis of the social skills improvement system (SSIS) for autistic children: Implications for use and educational placement

The Social Skills Improvement System Rating Scales (SSIS-RS) evaluates three domains of social functioning: social skills, problem behaviors, and academic competence. The SSIS-RS is a widely used social skills assessment for autistic children, but the validity of this measure for use with this heterogeneous population has yet to be confirmed. Using data from a previous large-scale investigation by the National Professional Development Center on Autism Spectrum Disorder, this study explored the factor structure of the SSIS-RS, examined how autistic children were rated using the SSIS-RS, and evaluated how scores on the SSIS-RS were related to special education placement. Confirmatory and Exploratory Factor Analysis examined the factor structure of the SSIS-RS for a sample of 492 autistic children, ages four to 12. An independent samples t-test using subscale scores of the SSIS-RS was conducted to evaluate differences between autistic children learning in different educational settings. Results of the EFA yielded a 4-factor solution and support the internal validity of the SSIS-RS. Subscale scores for social skills, problem behavior, and academic competence differed significantly between students in general and separate settings with academic performance scores differing much less than social skills or behavior. This study examines strengths and weaknesses of the SSIS-RS as a tool for assessing autistic children through discussion of items removed from and retained in the model. Discussion of results includes implications for teacher interpretations of SSIS-RS scores, recommendations for modifications to the measure, and insights about educational placement and inclusive programming.