Evaluation Psychometric Characteristics of the Persian Version of the Colorado Learning Attitudes about Science Survey Using polytomous Item Response Model

Goal: Researchers in the field of science education believe that peoplechr(chr('39')39chr('39'))s attitudes about learning will have a significant impact on their future learning and what they learn from science will not be unrelated to their views and attitudes. Accordingly, most questionnaires have been developed to measure attitudes toward science, especially about physics learning attitudes. One of the newest of them is the Colorado Learning Attitudes about science survey, it is known as CLASS. This questionnaire has not been standardized in Iran for the use of researchers in the field of education and psychology. Method: The research is descriptive based on instrument designs and examining the psychometric properties of the instrument, in this study, 476 high school students in science and mathematics course courses were used to evaluate the psychometric properties of the questionnaire. Confirmatory factor analysis was used to investigate the questionnaire structures and graded response model in Item Response theory was used to analyze items. Results: All 8 factors of the questionnaire were approved Cronbachchr(chr('39')39chr('39'))s alpha coefficient for all factors ranged from 0.701 to 0.891, while having a suitable fit with the polytomous model, had the desired diagnosis and threshold parameter. Conclusion: In terms of classical measurement indicators such as reliability and validity of the structure as well as the estimated parameters in the Item Response Theory, the items and structure of this questionnaire are considered desirable so researchers recommend use the Persian version of this questionnaire to examine attitudes about science, especially physics. They know it is appropriate.