DEVELOPMENT OF THE MARMARA CRITICAL THINKING DISPOSITIONS SCALE: VALIDITY AND RELIABILITY ANALYSIS
The purpose of this study is to develop a valid and reliable scale for identifying critical thinking dispositions. The study group of the research has formed 410 teachers working in the Istanbul/Pendik District. The Kaiser-Meyer-Olkin score for the 40-item draft scale was 0.932 and the Barlett test was 6476.72 (p<.001). The 28 items and 6 factors structure obtained as a result of exploratory factor analysis was confirmed by confirmatory factor analysis. Factors are called reasoning, reaching judgment, search for evidence, search the truth, open-mindedness and systematicity. The scale explains 56.35% of the total variance. The Cronbach Alpha internal consistency coefficient for all the scales is 0.91. The item-total and item-residual correlation coefficients are significant; the upper and the lower 27% group analyzes were found to be distinguishing the items and the factors. The correlation coefficients among the factors were found to be significant. As a result of the test-retest, the correlation coefficient was found to be significant for all the scales (r=.89; p<.001). The scale called Marmara Critical Thinking Dispositions Scale (MCITDS) was found to be a valid and reliable scale that measures general critical thinking dispositions.

Keywords
Critical thinking skills, critical thinking dispositions, scale development