The Spiritual Transcendence Index: An Item Response Theory Analysis

ABSTRACT

In an attempt to measure understudied dimensions of spirituality, recent efforts have focused on the transcendent dimension of spirituality. The Spiritual Transcendence Index (STI) was developed to assess a perceived experience of the sacred that affects one’s ability to transcend life’s difficulties. The main focus of the current study was to investigate the psychometric properties of the STI by utilizing the microscopic item-level examination tools unique in item response theory (IRT), as well as its scale-level exploration devices for psychometric properties of an assessment measure. IRT analyses were conducted to investigate the STI’s psychometric properties across samples (N = 712) including how well the measure assesses the latent construct, spiritual transcendence, from the low to high range of the construct. The findings confirm that the 8-item index is a single factor that assesses the latent construct, spiritual transcendence. Instead of the original 6-category version, these findings support a 4-category response version; the 3 categories of disagreement may be collapsed into a single category. These findings not only inform the refinement of the STI but also highlight an important psychometric approach for the refinement of spirituality/religiousness measures, especially those with ceiling effects.