Abstract:
Social validity is often defined as the degree to which an intervention has value to the community that it effects. Due to its impact on treatment effectiveness and acceptability, reporting social validity is critical to behaviour-analytic interventions. Authors use interviews and Likert scales to inform social validity. However, social validity is seldom reported in the literature. Most social validity questionnaires are created ad hoc based solely on face validity; whereas the standardised questionnaires available lack description of scale development procedures, particularly item generation. The purpose of this study was to evaluate methods for the development of a Likert scale to assess social validity, where item generation was not solely based on face validity. Parents and caregivers of children who took part in a study on behavioural treatments for children with feeding disorders were recruited to be part of an initial interview to inform scale development. Interviews were analysed using two different methods, (a) thematic analysis, and (b) textual analysis. The resulting themes were used to generate items for two social validity questionnaires. We examined the inter-rater reliability of the questionnaire development process and evaluated the content validity of each questionnaire. Of the two methods, the textual analysis had higher inter-rater reliability for producing themes that could be converted to items for a questionnaire. The textual analysis method also produced a questionnaire with content validity equal to that of the thematic analysis method. This demonstrates the successful use of a systematic, quantitative approach to the development of social validity questionnaires for behavioural interventions.