Conceptual problem-based learning model: Promising intervention to enhance prospective science teachers’ critical thinking skills

This study investigates the effectiveness and consistency of the Conceptual Problem-Based Learning model in enhancing critical thinking skills among prospective science teachers in the context of acid–base chemistry. Conceptual problem-based learning integrates explicit conceptual scaffolding with structured inquiry within a problem-based framework. A quasi-experimental, one-group pretest–posttest design was employed with 125 prospective science teachers from two Indonesian universities, selected through purposive sampling. Participants were organised into four intact classes and received the same Conceptual problem-based learning intervention in a Fundamentals of Chemistry course. Critical thinking skills were assessed using an eight-item essay instrument aligned with six indicators—interpreting, analysing, evaluating, inferring, explaining, and self-regulating—whose validity and reliability were confirmed (Cronbach's alpha = .722). Data were analysed using descriptive statistics, normalised gain (n-gain), paired-sample t-tests, one-way ANOVA, effect sizes, and Tukey's HSD post hoc test. Results showed significant pre–post improvements in critical thinking skills in all groups (p < .001), with n-gain values in the moderate range and very large within-group effect sizes (Cohen's d = 2.27–5.21). However, ANOVA indicated significant differences in critical thinking skills posttest between Group 1 and Group 4 and between Group 3 and Group 4 (p < .05), suggesting variability in Conceptual Problem-Based Learning's impact across classes. These patterns point to the possible influence of unmeasured factors such as group dynamics, motivation, and instructional mediation, and highlight the need for further research using more controlled and mixed-methods designs. The findings affirm CPBL as a promising pedagogical model for developing critical thinking skills in science teacher education while underscoring the importance of attending to contextual differences in its implementation.