Background and Objectives: Cognitive flexibility plays a crucial role in students' learning, stress management, and social interactions. This study aimed to validate its index among high school students.
Materials and Methods: This descriptive study targeted high school students in Shahroud during the 2022–2023 academic year. Using a multi-stage cluster random sampling method, one class from each grade level was selected from 12 schools, and all students in these classes were included in the study. A total of 1,076 valid questionnaires were collected. The cognitive flexibility index (CFI) was assessed through content validity, concurrent validity, structural validity, and reliability using Cronbach’s alpha and lambda coefficients. Data analysis was performed using Pearson’s correlation test, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA).
Results: The CFI showed a content validity ratio above 0.60 for 20 items, and item validity exceeded 0.80. Concurrent validity was confirmed by the significance of the Pearson’s correlation coefficient between the CFI and the Cognitive Flexibility Scale (CFS) (r=0.79, p<0.001). EFA extracted three main factors, explaining 52.70% of the total variance. CFA supported the three-factor model with goodness-of-fit indices such as a root mean square error of approximation (RMSEA) of 0.056. Cronbach’s alpha coefficient was 0.94 for the overall scale and 0.95, 0.95, and 0.77 for the dimensions, respectively.
Conclusion: The results of this study indicate that the CFI among students possesses suitable validity and reliability. Therefore, its application in future research and interventions, alongside other assessment methods, is recommended.
Keywords: Cognition, Psychological, Students, Psychometrics, Iran

Funding: This study did not have any fund.
Conflict of interest: None declared.
Ethical considerations: The Ethics Committee of Azad University of Bandarabbas approved the study (IR.IAU.BA.REC.1402.032).
Authors' contributions:
Conceptualization: Leila Bayat Mokhtari, Naser Mohammadi Ahmadabadi
Methodology: Leila Bayat Mokhtari, Naser Mohammadi Ahmadabadi, Alireza Kikha
Data collection: Alireza Kikha, Asma Bameri, Mostafa Rahdari
Formal analysis: Gholamhasan Panahi, Mohammadreza Mohammadi Soleimani
Supervision: Gholamhasan Panahi, Mohammadreza Mohammadi Soleimani
Project administration: Leila Bayat Mokhtari, Naser Mohammadi Ahmadabadi, Mostafa Rahdari
Writing - original draft: Leila Bayat Mokhtari, Naser Mohammadi Ahmadabadi, Alireza Kikha
Writing - review & editing: Leila Bayat Mokhtari, Naser Mohammadi Ahmadabadi, Alireza Kikha, Gholamhasan Panahi, Mostafa Rahdari