<![CDATA[This study examined the critical thinking skills of junior high school students on the topic of temperature and heat using the Rasch measurement approach to obtain an objective estimate of their abilities. A quantitative approach was applied, involving 53 students from a junior high school in East Nusa Tenggara Province. The research instrument was an essay test consisting of eight questions developed based on critical thinking skill indicators purpose, question at issue, assumptions, point of view, information, concepts, interpretation and inference, implications and consequences. The data obtained were subsequently analysed using the Rasch model approach with the Ministep software. The test results showed that the item reliability coefficient was 0.83, which falls within the ‘good’ category, while the Cronbach's alpha value of 0.60 indicated acceptable internal consistency. Item suitability analysis showed that most of the questions were in the category of fit to the Rasch model. Construct validity based on Principal Component Analysis (PCA) of the residuals showed that the instrument met the assumption of unidimensionality. In addition, the analysis of Differential Item Functioning (DIF) results showed no item bias between respondent groups. Mapping students' abilities using Wright Map and analyzing response patterns using scalograms showed variations in students' critical thinking abilities and a small number of respondents with inconsistent response patterns. These findings indicate that the developed instrument is suitable for mapping students' critical thinking skills on temperature and heat material, although further development is still needed to improve measurement accuracy at the individual level.]]>
