Convergent and Discriminant Validity of the Internalizing Symptoms Scale for Children

Abstract

The Internalizing Symptoms Scale for Children (ISSC) is a relatively new self-report measure designed to assess the broad domain of internalizing problems of children and to integrate the two- and three-factor models of affect proposed by Watson, Clark, and colleagues (cf. Watson & Clark, 1992). To date, limited research has been conducted investigating the performance of the negative affect/general distress and positive affect dimensions of the ISSC. The present research investigated convergent and discriminant validity coefficients between domain-specific self-report (RCDS, RCMAS, SSRS) and peer-report (PNID) measures with both the ISSC total and subscale scores. Validity coefficients support the continued use of the ISSC total score as a measure of distress that compares favorably with other commonly used measures. Correlations between ISSC subscales and other self-report measures indicate that the relationships between positive affect and negative affect and anxiety and depression proposed in the adult literature may also apply to children. Implications for clinical practice and future research are discussed.