Validating the Korean versions of the flourish index and the secure flourish index: a comprehensive psychometric...

Human flourishing is conceptualized as a state of complete well-being encompassing core dimensions of life: (D1) happiness and life satisfaction, (D2) physical and mental health, (D3) meaning and purpose, (D4) character and virtue, and (D5) close social relationships, and one sustaining domain, (D6) financial and material stability. As an indicator that enables policy debates on redefining priorities around what constitutes a better life, developing and validating Korean translations of this measure is essential for meaningful international comparison. Therefore, this study aims to validate the Korean versions of the Flourish Index (FI) and the Secure Flourish Index (SFI), providing psychometric evidence and culturally grounded insights into the multidimensional construct of flourishing.

A total of 1,217 adults participated in an online survey conducted between January 30 and February 8, 2024. To ensure comprehensive validation, reliability and structural validity were examined using classical test theory, while item-level functioning was evaluated using unidimensional and multidimensional graded response models within an item response theory framework.

The findings supported the conceptual and structural validity of both indices while indicating multidimensionality. Specifically, three domains (happiness and life satisfaction, mental health, and meaning and purpose) clustered closely and primarily contributed to the general flourishing factor. In contrast, character and virtue and close social relationships formed a distinct cluster, implying a potential personal-relational distinction. Items in the character and virtue domain showed signs of social desirability bias, while redundancy was noted between items in the close social relationships domain. Measurement invariance was supported at the configural and metric levels, and partially at the scalar level, and no significant differential item functioning was detected.

These findings imply that culturally sensitive adaptations may enhance the interpretability and applicability of the instruments in cross-national research, thereby contributing to a more nuanced understanding of flourishing across diverse cultural contexts.