Exploring the Relationship Between Critical Thinking Levels and Learning Obstacles in Students' Understanding of Solid Geometry: A Descriptive Study

This study examined junior high school students' critical thinking skills and learning obstacles in solving problems involving the surface area of geometric solids. A descriptive design integrating quantitative and qualitative analyses was employed with 71 ninth-grade students from one public junior high school in Cimahi and one private junior high school in Cilegon, selected through purposive sampling. Data were collected using a written test comprising three questions with 12 sub-items, designed to assess six critical thinking indicators based on Facione's framework and validated by experts, and through learning document analysis. Quantitative data were analyzed descriptively using scores and categories for each indicator. Qualitative analysis focused on students' written responses to identify reasoning patterns, errors, and learning obstacles, which were classified using the Didactical Design Research framework. The findings revealed that students' overall critical thinking skills were low. Interpretation and analysis were at a moderate level, evaluation and explanation were low, and inference was very low. Self-regulation could not be adequately identified through written responses. The identified learning obstacles comprised epistemological and ontogenic obstacles, including conceptual, instrumental, and psychological dimensions. These findings highlight the need for geometry instruction that connects conceptual understanding, spatial visualization, and mathematical reasoning to address students' difficulties and support the development of critical thinking skills.