Psychometric properties of Grit-S scale in university students: An application of the graded response model

This study adopted an item response theory to evaluate the Grit-S scale and its dimensions (i.e., Consistency of interest [G-CI] and Perseverance of effort [G-PE]) among university students (N = 450) using two unidimensional Graded Response (GR), multidimensional GR, and bifactor GR models. Differential item functioning (DIF) across two countries (Oman and the United States) was investigated. For G_CI, the findings showed acceptable values for item discrimination, trait thresholds, reasonable precision in both samples, and two uniform DIF. The findings of G_PE showed two questionable item-discrimination parameters (Items 7 and 8) in the two samples, two non-uniform (i.e., Items 5 and 8) and two uniform DIF (i.e., Items 6 and 8). Acceptable precision was found only in the U.S. sample. Item 8 was the source of imprecision in the Omani sample. These results indicated that further modification is needed to improve the precision of the scale in the Omani culture.

Automated summary

This study used item response theory to evaluate the Grit-S scale and its dimensions among university students. The findings showed acceptable values for item discrimination and trait thresholds, but further modification is needed to improve precision in the Omani culture.