Psychometric Investigation of the Cultural Intelligence Scale Using the Rasch Measurement Model in South Korea

As the business environment and its workforce’s composition have become more diversified, more attention has been paid to cultural intelligence or the ability to effectively function in such an environment. Various attempts have been made to measure and develop leaders and staff members’ cultural intelligence. The Cultural Intelligence Scale (CQS) is the most representative tool for measuring cultural intelligence worldwide and has been frequently used in South Korea. Although CQS validity has been verified for each country and cultural region, it has been used without psychometric verification in South Korea and simply translates the original scale into Korean. This study’s objective was to test CQS validity when employed with the employees of South Korean companies. It applied the Rasch measurement model to confirm the validity in various aspects. First, this study calculated an item adequacy index and performed point biserial correlation analysis. The results showed that all values were above the appropriateness threshold. A Likert scale response test was conducted to check actual validity. The results confirmed that the 7-point rating scale was valid, and the item–subject map proved that the CQS items reflected the respondents’ ability distribution relatively well. Rasch factor analysis for confirming the internal structure’s validity revealed that CQS showed a multidimensional factor structure. Lastly, this study checked differential functioning items by position to secure evidence of generalization validity. It was confirmed that it has an appropriate level of generalization-related validity.