Abstract: Interventions (such as participatory arts projects) aimed at increasing social inclusion are increasingly in operation, as social inclusion is proving to play a key role in recovery from mental ill health and the promotion of mental wellbeing. These interventions require evaluation with a systematically developed and validated measure of social inclusion; however, a “gold-standard” measure does not yet exist. The Social Inclusion Scale (SIS) has three subscales measuring social isolation, relations and acceptance. This scale has been partially validated with arts and mental health project users, demonstrating good internal consistency. However, test-retest reliability and construct validity require assessment, along with validation in the general population. The present study aimed to validate the SIS in a sample of university students. Test-retest reliability, internal consistency, and convergent validity (one aspect of construct validity) were assessed by comparing SIS scores with scores on other measures of social inclusion and related concepts. Participants completed the measures at two time-points seven-to-14 days apart. The SIS demonstrated high internal consistency and test-retest reliability, although convergent validity was less well-established and possible reasons for this are discussed. This systematic validation of the SIS represents a further step towards the establishment of a “gold-standard” measure of social inclusion.
Keywords: internal consistency; mental health; psychometrics; scale validation; social inclusion; Social Inclusion Scale; test-retest reliability; validity