Validating the nonparental adult inventory (NPAI) for mental health assessment and research.

Survey data collected from 518 parent-adolescent dyads were used to examine the psychometric properties of the NonParental Adult Inventory (NPAI). Test-retest reliability, internal reliability, and factor structure were examined. Reliability analyses indicate adequate to good test-retest reliability and internal consistency. Exploratory and confirmatory factor analyses support three-factor models that differ for parent and adolescent samples, both of which explain approximately 54 % of the variance. The NPAI reveals a three-factor structure that clearly differentiates between related and nonrelated adults in both adolescent and parent samples. This scale may be useful to both practitioners in assessment procedures and researchers for use in multivariate analyses.