Psychometric Evidence and Measurement Invariance by College-Going Status for the Inventory of the Dimensions of Emerging Adulthood (IDEA).

Numerous versions exist of the Inventory of the Dimensions of Emerging Adulthood (IDEA), which is used to assess normative markers of development in the 18-29 age range. However, their comparative psychometric properties have not been adequately explored, and samples including non-college-going emerging adults are rare. In Study 1, confirmatory factor analyses using survey data from 429 college-going and non-college-going emerging adults (52% female, 44% non-white) showed the IDEA-Short Form (IDEA-SF) to be the most psychometrically and conceptually sound version, demonstrating good fit for the five-factor model proposed by Arnett's (2004) theory of emerging adulthood; initial evidence for concurrent validity of the IDEA-SF scores was also presented. Study 2 (N = 765, 40% non-college-going) tested and found evidence for internal reliability and convergent validity as well as measurement invariance across college-going and non-college-going emerging adults for the IDEA-SF, though evidence for discriminant validity was mixed. Study 3 (N = 817) used data from the openly-available EAMMI3 dataset to examine concurrent and discriminant validity evidence for the IDEA-SF scores with multiple measures of well-being and adult development, respectively; preliminary, albeit weak, evidence of both forms of external validity was found. Suggestions for future research employing and improving the IDEA-SF and clinical implications for mental health clinicians working with emerging adults are discussed.