The effect of the STEM approach with the formative assessment in PBL on students' problem solving skills on fluid static topic

The use of problem-based learning with STEM and formative assessment (PBL-STEM-FA) to overcome the weakness in students' problem solving skills (PSS) is still limited. This research investigates the effect of PBL-STEM-FA in students' PSS in the topic of fluid static. This research uses the pretest-posttest non-equivalent group design, and involves the research subject of class XI high school students in Malang, Indonesia. Experiment class' students make engineering products in the form of miniature boats. The PSS test instrument with 0.799 reliability were used in this study. The data were analyzed by independent t-test, Hake-gain, and Cohen-effect. The results showed that students of PBL-STEM-FA class had significantly higher PSS and N-gain than students of PBL class. The highest raise occurred in the Useful Description indicator and hydrostatic pressure subtopic for the Experiment class; and Useful Description indicator and surface tension subtopic for Comparison class. But, the two classes had the same lowest raise, namely in the Mathematical Procedures indicator and capillaries subtopic. The effect size at 0.651-medium category implies that the implementation of PBL-STEM-FA is recommended to be carried out in the field to increase students' PSS. It is recommended that future studies add an "Art" aspect to the STEM approach.