Contextual Chemistry Practical Training for Secondary Science Teachers: Bridging Infrastructure Deficits Through Problem-Based Learning

This article evaluates a 10-hour community-service training program organized by Mulawarman University for 13 junior-secondary (SMP/MTs) science teachers in North Samarinda, Indonesia. The program supported teachers in designing contextual chemistry practicals integrating Problem-Based Learning (PBL), Science Process Skills (SPS), Higher-Order Thinking Skills (HOTS), and Claim–Evidence–Reasoning (CER). The pre-test mean was 96.15/100 (n = 13), whereas the post-test mean was 88.89/100 (n = 9). Post-test item analysis showed strong performance on HOTS classification and worksheet design, but errors remained in identifying dependent variables (44.4%), selecting control variables (33.3%), and selecting quantitative evidence for CER explanations (55.6%). The findings suggest that low-cost contextual practicals offer a feasible basis for teacher professional development, while variable control and quantitative evidence-based reasoning require further guided practice and follow-up support.