Investigating the Effectiveness of Learning by Research Model in Promoting Students’ Critical Thinking Skills

Abstract

This study examined the effectiveness of the Learning by Research (LBR) model in improving junior high school students’ critical thinking skills. The study was conducted at SMP Negeri 66 Jakarta between January and April 2026 using a quantitative quasi-experimental design with pre-test and post-test measures. Two classes were involved: Class VIII-D served as the experimental group and received instruction through the LBR model, while Class VIII-G served as the control group and received instruction through the Direct Learning model. The LBR intervention engaged students in research-oriented learning activities, including problem orientation, research design, exploration, data analysis, conclusion drawing, and exhibition of research findings. The learning activities were implemented in the context of science and social studies topics related to food consumption, sugar content, lifestyle patterns, diabetes mellitus, and chronic kidney disease among adolescents. Students’ critical thinking skills were assessed using a test instrument based on critical thinking dimensions, including interpretation, analysis, evaluation, inference, and explanation. The instrument was reported to have been validated by experts, with a validity score of 90% and a Cronbach’s alpha reliability coefficient of 0.91. The results showed that both groups improved from pre-test to post-test; however, the experimental group showed a greater increase. The control group’s mean score increased from 55.88 to 67.63, with an average N-gain of 0.27, while the experimental group’s mean score increased from 56.90 to 82.70, with an average N-gain of 0.62. Normality testing indicated that the N-gain data were normally distributed, while the homogeneity test indicated unequal variances between groups. Therefore, Welch’s independent samples t-test was used and showed a significant difference between the groups (p < .001). These findings indicate that the LBR model was more effective than Direct Learning in improving students’ critical thinking skills in this study context.