Reliability, Validity and Factor Analysis of Rickett's Critical Thinking Disposition Scales in High School

The importance of critical thinking disposition in educational system and curricula at levels prior to higher education is indicative of the need for a short-form tool to measure this construct. The aim of this study was to investigate the reliability, validity and factor structure of Rickett's (2003) Critical Thinking Disposition Questionnaire among high school students. In this descriptive-survey research, 472 high school students (270 girls and 202 boys) in Mashhad in the school year 2010-2011 were selected using multistage cluster sampling, who completed Critical Thinking Disposition Questionnaire. The validity of the questionnaire was assessed using content validity, construct validity and factorial validity.The reliability of the questionnaire was examined by internal consistency and split-half method. Cronbach's alpha coefficients were calculated for all scales and subscales for both genders and all subjects with regards to favorable psychometric properties. All correlations between subscales and total scale score were significant. The results of confirmatory factor analysis indicated that the items were good fit. Moreover, the result of split-half method showed that reliability coefficient of the test was satisfactory. The results of the study showed that the Persian version of the Critical Thinking Disposition Questionnaire has a good reliability and validity in Iranian society and is an appropriate instrument for assessing critical thinking disposition in high school students.